It can go either ways. And it will solely depend upon how the new company will handle the game.
The first thing which came to my mind after knowing the news is that Niantic planned this deal last year most probably, considering that they introduced Game Pass like things, which are prominent in the other games. So thinking it this way, the idea of does aligns with the deal made. So if this is correct, then there might not be much changes in the game, although this also means that there will be more Event Pass like stuffs in the future, which will award Mythical Pokemon.
This sounds bad to me, as Mythical Pokemon are the only Pokemon which are provided to all players for free via Special Research, and paid Masterwork Research for getting their Shiny Variant. Plus I didn't liked the idea of Tour Pass which was introduced in this GO Tour as well(for the free version), and the paid version was grind to get one Lucky Trinket, excluding the XL candies.
So I expect more micro-transactions in the foreseeable future.
And if think in the optimistic way, then I can say that the new company will enhance some aspects of the game as well, considering that Niantic was focused on collecting Map Data, whereas this company isn't. So "it might be" possible that some good QoL features and gameplay experience improvisation will come in the game. But these are too much optimistic! Even the original developers of the game failed to implement many of the demands from the playerbase in these 9-10 years.
Another thing is about privacy policy of the game. Because location and map data are very sensitive information as they are collected real time. Therefore, there should be clarity regarding how our data will be processed under this new company.
According to the blog of Scopely, they did told that game will remain like it was, hence it will be only matter of fact how the game will behave under their ownership. Most probably, GO Fest 2025 will be the last event maintained by Niantic, hence the new season will give us the idea regarding how Pokemon GO will turn out under this change.