I've actually suspected this tbh. It could be this guy who Whitebeard was based on, he died 2-3 years before Marineford happened:
But I think it would be due to someone else if it is for that reason ofc. Although then again, he wrote Whitebeard to be so truly grand, noble, majestic, epic, badass etc and gave him the most glorious send off I've ever seen for a character.
I randomly saw a certain major death scene from Seven Deadly Sins that kinda reminded me of WBs death, it was grand, tragic, beautiful and poetic and even though I've not checked out the series, it made me very emotional too:
Araki went through a really dark phase during Part 5 of Jojo apparently:
https://www.reddit.com/r/StardustCrusaders/comments/akxc1c/_/ef8qije
I feel something like this happened for Oda too for whatever reasons that caused it. When he was writing Sabaody to Marineford, it just felt like OP was getting far more darker, serious and just different in tone, it was a horrifying time imo. Sabaody lowkey traumatised me then Marineford did the same again for different reasons. I know its quite an extreme reaction but I really deeply invested in OP and those events broke me pretty badly. I really feel Oda was in such a dark place writing those arcs. I've not researched it though.