One for Pokémon and one for Astral Chain.
After reporting a Switch revision was in the works for 2019, sources have indicated to the Wall Street Journal that there may in fact be two Switch revisions.
The report (subscription required) posits that the revisions would be announced at E3, and release later in the summer. One revision would be a less expensive option and would serve as an upgrade path for the 3DS, but would omit HD Rumble. The other would be a "Pro" Switch that may be more powerful than the current model, though not at the level of a PlayStation 4 Pro, and would include features more appealing for core gamers.
Reported in the same article is that Sharp is bidding to be the display supplier for the revisions, replacing a combination of three firms. Sharp previously was the display supplier for the 3DS.