I never said DJ wasn't in the GOAT discussion. But a lot of people, including me, can't have him as THE best fighter of all time based off who he beat. That's why GSP, Anderson, and Jones frequently outrank him on those lists. If Islam beats JDM and Topuria defends the LW title like 1 or 2 more times, I guarantee you people would probably hold them in higher GOAT rankings than DJ too. This was the same issue Ronda had with her weak, up and coming female BW division. Massive win streak, but most people can't even remember half the names she beat.
With Aspinall, I know we are talking strictly about him as a HW GOAT if he beats the record. But the same logic applies. If he beats the HW defense record by beating Gane, Volkov, Almeida, and Cortes-Acosta (current top 5), is anyone really going to consider that a better record than the record of previous HW fighters like Ngannou, Stipe, Werdum, JDS, Fedor, Overeem, or Cormier? Some of those fighters never won UFC HW gold, but they still have far better win streaks and records than the likes of Gane, Volkov, Almeida, and Cortes-Acosta. I think Cain has a pretty weak record at HW, and I'd still say his record is better than those list of names.
HW is in a pretty weak state right now. The past two title winners (Jones and Ngannou) never even fought each other, and Aspinall will likely never face either of them. So he's in the position of being a paper champion's paper champion just by way of title lineage. Its not his fault, but beating the likes of Gane, Volkov, Almedia, and Cortes-Acosta definitely isn't going to help him overcome that stigma.