It'd be too little too late.
As I said previously when we discussed this, Roman's legacy does not rely on scrubbing Hogan's record. It's not even mentioned outside of forums like this one. Roman's already cemented his legacy as one of the genuinely greatest wrestlers of all time. He doesn't need to break Hogan's record to cement his legacy.
The fans love Cody, absolutely. But there's only so long fans will tolerate a slow burn approach to him finally getting the win before they just run out of steam for Cody and the product as a whole, say "f this" and just turn the TV off. Reigns' title run has run its natural course. Hell, it ran its natural course last year if you really ask me. Another year, if anything, is gonna get so stale that Roman's title reign is gonna end on a whimper which would hamper his legacy more than it ending with a bang at WM 40. WM 40 is the best place to end the title run. It ends with a satisfying climax, cementing both the legacies of Cody and Roman, and sets Roman's run as quite possibly the greatest WWE championship reign of all time.
To me, where you go after Cody wins is honestly fairly simple.
Have LA Knight win the Elimination Chamber and in turn win the WHC, swapping the brands for the titles. Then, continue Cody vs the Bloodline...
but extend it into a brand new brand warfare in the most literal sense. Cody Rhodes' Raw vs Roman Reigns' Smackdown. It writes itself.