Konami on board with NSO would be good news for the N64 selection. I know Castlevania Bloodlines is on the Mega Drive selection, but I think this is the first Konami addition since then.
Bomberman 64 and Bomberman Heroes were published by Nintendo back in the day and I think they both made their way to Wii Virtual Console at the very least, so I'd peg those two as firm possibilities given Konami now hold the rights and it's difficult to see how else they'd get re-released. Castlevania 64, Legacy of Darkness and Mystical Ninja Starring Goemon would be the other choices and none of those games have had a re-release in the past. I don't think we'd see Nintendo and Konami launch those titles all at once, or as part of the same yearly wave; I think it's far likelier they'll be part of a sporadic schedule over the next few years. But they would widen the pool of releases and make it easier for Nintendo to do another half dozen N64 games each in 2024 and 2025.
I'd say Smash Bros, Donkey Kong 64, Cruis'n USA and Blast Corps (given it was planned for Wii U) remain the likeliest first-party additions in future, and I still feel pretty bullish about Nintendo and Microsoft reaching a deal with Diddy Kong Racing. I think if further Rare games are coming, though, they're going to be spread out. Add some random third-party license - I'd pick Atlus for Snowboard Kids and Ogre Battle 64 - and you've got a good selection of games to go through the next couple of years. If we got Harvest Moon 64 as an international release rather than Japan only, and counting Excitebite 64 as well as my hypothetical picks for 2024-25, we'd end up with an N64 selection of around 40 games without too much difficulty on Nintendo's part, I think; double what either Virtual Console achieved.
As an aside, we've now had a GB/C addition on a monthly basis 5 months on the bounce, which is good (but not brilliant) for the base tier.