Browser support is the most important factor for web video. H.265 currently has no browser support but VP9 is supported by Firefox, Chrome, Microsoft Edge, Opera, Vivaldi, etc.
I'd say there's a reasonable chance, and if not VP9 then definitely AV1. The next version of macOS and iOS supports WebP (a still image format based on VP8) so the VP8/VP9/AV1 family has a foot in the door:
