I wouldn't get caught up on Nintendo not having their 'own' games out the next few months, though I agree the first half of 2023 looks a little odd. They've just launched a major internal game, and while Ubisoft do the heavy lifting on Sparks of Hope, it's a Mario game - it doesn't exist without Nintendo's say so and it has the October slot that's almost always been occupied by a Mario series title during the Switch era (Odyssey in 17, Party in 18 and 21, Luigi's Mansion 3 in 19, 3D All Stars in late September 2020). That's too consistent to be anything other than a deliberate strategy and I suspect Nintendo and Ubisoft worked together on the release timing. And again, Bayonetta 3 doesn't happen without Nintendo; Sega's IP ownership is immaterial when Nintendo fund and produce the game. Same deal for Pokemon, where Nintendo co-own the IP. It shouldn't surprise us that, as games development gets more complex, Nintendo's release schedule and development arrangements reflect that. Relatively few holiday seasons have leant on major internal titles from Nintendo on Switch - usually Game Freak and other affiliates and subsidiaries do the heavy lifting at that time of year.
Finally, while I think the year's line up is really strong, this year actually has the second lowest number of first party releases on Switch; only 2017 had fewer. Some of that is down to there (so far) only being one eShop release, but the year isn't really "full" the way other years have been. Like 2017, it's been consistent, varied, and well-paced; like 2019, it's pleasing to have a lot of brand new software without ports filling the schedule. I'd also say Fire Emblem, Kirby and Zelda is a strong start to 2023. Those games are out by mid May, and they're three key franchises, and you can bet Octopath Traveler 2 while multiformat will perform strongly on Switch. Some of the gaps are suspicious - especially March 2023 - but the pacing of key titles into next year seems pretty consistent with the pace they've settled on since late last year.