I think Switch was a good lesson that, if the software's not ready, then pushing the launch back a few months to polish it can be a good choice in the long run. Unless the software they were polishing was 1-2 Switch, in which case maybe it wasn't such a good choice.
Let's say Nintendo were developing [redacted] with a targeted release of Q4 2023, and along the way a spanner (COVID) got thrown in the works, and launch software isn't quite where Nintendo wants it to be in early 2023. The situation is a bit different than it was for Switch. At that stage Nintendo had the 3DS, which had a healthy lineup for Q4 2016 regardless of the Switch launch, and the Wii U, which honestly was barely part of the equation by that stage. Now, though, the Switch, although declining in hardware sales, has a pretty healthy audience for software, and with cross-gen games and backwards compatibility, the Switch and [redacted] lineups are closely intertwined.
If Nintendo had planned a suite of cross-gen titles as part of the launch window of [redacted], then they might be in the unusual position where delaying [redacted] could either mean either a weaker lineup for the Switch in Q4, or a weaker launch lineup for [redacted] when it does launch.
As an example, let's consider that one of Nintendo's planned releases for Q4 2023 is Mario's Pasta Simulator, where players can put all kinds of crazy ingredients on their pasta. This is planned as a cross-gen title, running perfectly fine on Switch, but with 4K graphics and ray tracing on [redacted] so that you can really appreciate the glisten of the cumin as you carefully shake it atop your pasta. Nintendo have to figure out what to do with Mario's Pasta Simulator. If they delay it alongside [redacted], then they're missing out on a big Switch holiday title at a time when Switch software sales are still very strong. If they decide to release it as a Switch title, then they've lost a big launch window title for [redacted]. They can of course still release an update for it with all the fancy [redacted] graphics they had planned, but a patch for an existing game isn't nearly as good a selling point for new hardware as a whole new game.
I do wonder if part of the reason Nintendo have almost nothing announced past July is that they have games which they're just not sure how to announce. If a game is planned as a cross-gen title, then it's best to announce it as such and put as much emphasis on the next gen version as possible (with games like God of War Ragnarok and Horizon Forbidden West, Sony barely even acknowledged the existence of the PS4 versions). Some of those may have to be announced just as Switch games, though, if the alternative is an empty second half of the year. If the launch date of [redacted] is still in flux depending on the development of one or two major launch exclusives, then there are potentially knock-on effects for a lot of other games.