I said RiD Grimlock (aka Build Hurricane), not RiD2015 Grimlock. I'm not saying that the homage to G1 Ultra Magnus isn't there in God Magnus, but I just don't think that it was really intended to be a direct version of Ultra Magnus. Rather a new character who is inspired by or is intended to be a tribute to Ultra Magnus.

Don't forget that God Magnus is also a tribute to Godbomber, the Autobot who combines with Ginrai to form God Ginrai. Like Godbomber, God Magnus combines with Fire Convoy to form God Fire Convoy. When they combine, they say 超巨大合体ゴッドファイヤーコンボイ ("Super Giant Merge, God Fire Convoy!"). This is similar to the activation command for when Ginrai and Godbomber merge by saying, 超神合体ゴッドジンライ (Super God Merge God Ginrai) And of course, Godbomber comes from the series 超神マスターフォース (Super God Masterforce). This is why his name is God Magnus, and not "Ultra Magnus" nor "Godbomber." It's a double homage to two characters. And of course, God Magnus' personality is nothing like any Ultra Magnus that's come before or after. This may be subjective but I personally don't see him as an Ultra Magnus.

One (but not the only) reason why Hasbro probably changed the name from God Magnus to Ultra Magnus was likely because they wanted to avoid using the word "God" in fear of offending conservative religious parents. This is likely why Hasbro's release of reissue Godbomber was called "Apex Armour." Oh my Apex!