In terms of Capcom, like I said it worked out for Monster Hunter World. But we are still to see it work out consecutively, which is more important for the long term longevity of this strategy. For example, if the sequel isn't able to sell as well WW, it could spell trouble for the company.
Let's say MHW 2 is a cross-gen time-exclusive on the PS4/PS5 it's pretty unlikely it would do better in Japan than Monster Hunter World. This is why the strategy is risky because Western audiences might have moved on to something different since MH isn't a staple in the West.
The bigger question is the rest of their franchises. Resident Evil, Devil May Cry, Street Fighter, Dragon Dogma, Ace Attorney so far are just getting old ports to the Switch. This is the bigger omission since outside of Resident Evil most of these games are struggling to reach 5M worldwide, so any additional sales would have been welcomed.
Koei Tecmo's main issue is that "Warriors" games have been declining for years now. Their alternative Nioh has not been ported to the Switch and neither has Dynasty Warriors 9. Overall they are in a particular position because in the past most of their portable output was on PSV and not on 3DS. I'd say they are doing their best to move everything on the Switch. But they really need to think about new IPs with different formulas Warriors games might be cheap to make but so far we haven't really seen them popular enough to even break 200K on the Switch in Japan.
Hyrule Warriors on the Wii U/3DS/Switch remains their best selling game on a Nintendo system with its three versions totalling to 288.033.
While Atelier is the only franchise which has seen growth in the last few years from Koei Tecmo's perspective with it being a simultaneous launch on the PS4/Switch it sold over 400K World Wide.
PS3 TOP 5
PSV TOP 5
PS4 TOP 5
3DS TOP 5
Switch TOP 5
Capcom is definitely on thin ice, since they used up all of their remasters I think. We can hope they get their act together and create some new games like they did with the MH franchise and Dragon's Dogma.
Koei Tecmo is fine since they have so many deals with other companies. Nioh is clearly the Sony PS thing, Fire Emblem Three houses on Switch for Nintendo did great, Dragon Quest Heroes for SE was great, One Piece Pirate Warriors for Namco Bandai etc. I wonder what their next collaboration will be.