Was Kano Ryu Jujutsu EVER a thing?

So in the ongoing campaign to muddy the waters of Martial Arts History, one of the stickier red-herrings seems to be the existence of so-called "Kano Ryu Jujutsu".

You mean ... "Kodokan Judo" I say ... or think .... or yell at the computer screen as the case may be.

Most of this seems to do with BJJ being loathe to admit that Maeda (or even Kimura... ) was (were) a Judoka.

So reference get's made to Kano Ryu Jujutsu. It seems clear that when Kano opened the Kodokan he was teaching jujutsu at first, although its unclear which of the several ryu he learned that he was teaching. It also seems clear that by the time he made up his mind he was forming his own school, that it would be called Judo and not jujutsu.

Was there really any period when "Kano Ryu Jujutsu" was a thing?

Is it not rather insulting to Kano to rename his creation, other than what he himself called it, even if it is to name it after him?

Would love to get a definitive answer on this.

Very interesting question

This has several layers so needs long discussion.
1. No Kano did not ever at any point name any "style" after himself. This did not, however prevent others on using Kano to distinquish the "style" e.g. Judo : manuel de jiu-jitsu de l'ecole Kano a Tokio. by Yokoyama, Sakujirō (1864 - 1914): Oshima, Eisuke, Paris France, Berger-Levrault, 1911, xi,209p or The complete Kano Jiu-Jitsu (Judo). Hancock, Harrie Irving (1868 - 1922): Higashi, Katsukuma, New York, United States, G. P. Putnam & Sons, 1905, 526p. As a matter of fact there are several names untill one settles for Kodokan Judo.
2. There is ample reference that Kano wanted Judo to be separate thing from jiu-jitsu. He thinks that jiu-jitsu to be a little more than brawling whereas Judo has higher educational aims. But again this did not prevent people from referencing his school as jiu-jitsu as this term had gained ground in the west. IMHO the term jiu-jitsu was not the term the judo practitioners defined or used of other ruy.
3. You want to get a definitive answer and sorry there is no definitive answer to "Was there really any period when "Kano Ryu Jujutsu" was a thing?" because that involves time, place and group which also can be ethnic. Because of Hancock there was IMHO false reference to  The complete Kano Jiu-Jitsu (Judo) but does that mean we still should use that term.
Maybe some others can join in e.g. What was Kodokan Judo called in the period newspaper articles in Japan?

Edit: BTW I think it is completely dishnest to reference Kodokan Judo as "Kano style jiu-jitsu" because that distorts the ruy, the history and the way we discuss things.

Very nice reply by Finarishi, thank you.

A large part of the confusion can be laid at the feet of the simplistic Kodokan histories, too. They typcially read something to the effect 'Kano shihan opened the Kodokan in 1882 and began teaching judo.'

There's no indication he was even teaching in the earliest days of the Kodokan - first he opened his juku, a private school that continued for decades, and some months later the records note he began practicing jujutsu with a small number of those students, but apparently with guest jujutsu instructors. I've not seen the claim that he alone taught, but there is mention time to time of outside instructors. They could have begun practicing from day one but that fact is apparently not recorded, just that the 'Kodokan' was established some months after the juku.

Judo evolved and was created over an extended time of decades, as was the current history. During that period apparently jujutsu training continued apace. Kano shihan himself mentions the participation of a number of different jujutsu masters from a number of specific and other unspecified schools / ryuha in the search for different techniques.

Newspapers of the late 1890s might start with jujutsu in an article's title then shift to judo interchangably. By the early 1910s judo pretty much predominates as the generic term while jujutsu is still used for kobudo jujutsu ryuha, but you can still find the odd mention of 'Kano ryu judo' to further confuse things even later.

Later in his life all that detail is pretty much forgotten, as Kodokan judo or Schoolmaster Kano's judo becomes the typical citation, and Kano shihan himself simply says he opened the Kodokan and began teaching judo.

By the time Kano shihan retired in 1920 from his post as school principal at 59 and stops wearing keikogi, everyone around at the beginning was either dead or a firm Kano supporter, or even employed by the Kodokan, so no one ever seems to correct him.

By the time of Kano shihan's death in 1938 at age 77, Nango Jiro, his nephew, 61 years old, the second Kodokan president, wrote that he was after shihan's death then the second most senior judoka left alive. I assume he meant the most senior student was Admiral Yonai Mitsumasa, then Navy Minister, later Prime Minister in 1940. Yonai was a bit younger than Nango but apparently started judo earlier, and participated in certain Kodokan ceremonies in which he represented all judo students. Yamashita Yoshitsugu, the last of the 4 Heavenly Kings of the Kodokan, had died 1935.

BTW I just found an article which cites Nango put on a keikogi and began practice in 1939, for the first time in 30 years, at age 62. I guess he never got promoted again and remained 3 dan.