No, it's an opinion. And a weak one at that.
I've never heard of either Loz or Pete before, and barely heard mention of RQ6 (except disparagements by HQ and RQ1-3 fans and hints of same by Greg Stafford in his KS vids). I've looked at the RQ6 mechanics in a friend's copy... and it's not innovative, it's not impressive, and not terribly different from MRQ II. Further, it's not well known
Your first comment, which essentially claims ignorance, somewhat disqualifies your second. I don't think you have read it, don't know about it's innovations or qualities at all and, following on, your 'version of events' is quite wrong. Here is a review by somebody who has actually read it:
https://www.youtube.com/watch?v=08qYDH9BYOQ
Mongoose's Matthew Sprague did more than this Pete or Loz - by unethical means, but still- He acquired the trademark, he sunk a huge lot of money into it, he secured a license from Greg - who, no matter your opinion, is the legal owner of the Glorantha setting under the relevant copyright laws (to wit, US and UK). His acquisition was legal, and he used the Trademark to coerce Greg (both Greg and Matthew have stated this more politely in public posts) into licensing Glorantha non-exclusively to Mongoose, in exchange for return of the Trademark to Greg.
I'm not sure what is unethical about legally securing a license from Issaries Inc (Greg Stafford) and you are making up in your head any form of 'coersion' (indeed, I'd be careful what you write, as if any of the parties are reading this they might consider it libellous). Glorantha products were produced by Mongoose in the '2nd Age' as part of the license to avoid conflict with the classic '3rd Age' that was developed by Moon Design (also licensed by Greg Stafford). And for the record, the RuneQuest rules were not a major credit for Greg Stafford - Steve Perrin and Ray Turney were the main game designers.
Pete and Loz, or whomever, made use of Matthew's having made MRQ and MRQII open source, and a license from Greg that was not well publicized. They rode other people's work. They may or may not have made significant efforts. They may or may not have shared Greg's vision for Glorantha. But they MOST CERTAINLY DID NOT do as much to bring RQ to the public consciousness as Matthew did.
Mongoose's RuneQuest was released as open license, but RuneQuest II was not. Mongoose RQ1 was written 'by committee' with Matt Sprange as the lead designer, and indeed it was Pete and Loz who actually persuaded Matt to pick up the license in the first place. MRQ2 was written by Lawrence Whittaker as the lead designer, who had written for Chaosium many times before. By Mathew Sprange's own admission, 'what Lawrence Whittaker didn't know about RuneQuest wasn't worth knowing' and this was why he handed the reigns over to him, when criticisms of MRQ1 had surfaced. Pete Nash won awards for his writing too, especially his historical books, and is also well immersed in BRP/RuneQuest publications. The reasons why MRQ2 didn't continue (outside of the Legend brand) were not made public, but unlike MRQ1 it was praised for it's content.
RuneQuest 6 was licenced from Issaries again to TDM as a new company directly set up by Lawrence Whittaker and Pete Nash to create a new and authoritive RuneQuest game. It earned strong reviews and critical feedback from all quarters. It had a written endourcement from Steve Perrin (one of the original game's designers) in the Preface. They did all this off their own backs, without any assistance from Chaosium, Mongoose and only cursory involvement from Moon Design. They had worked closely in collusion with Moon Design towards a (now vapourware) supplement called Adventures in Glorantha for the last two years. This product was announced in August to have been expanded out to a whole new edition of RuneQuest for Chaosium (ie Moon Design had originally commissioned TDM to write it when all the licenses had fallen to them). This latest announcement has changed course.
What you are writing is incorrect. Moreover, you are also quite directly engaging in the sort of edition warring that, even with the various confusing editions of recent years, the BRP community had largely been free from - it's not like Traveller!
You are evidently wrong insofar that the creative director for Glorantha, Jeff Richard, at Moon Design/Chaosium has already stated that Pete Nash and Lawrence Whittaker will be credited in the new edition. The quote in the article was from the context of trying to assuage fans that the new edition would not ditch their innovations to the game in the new edition.They are among the foremost experts on the Gloranthan setting and the RuneQuest system in the world. If you don't know who they are, then you simply don't know much about RuneQuest.