Yup, the engine will be RPG Maker MZ instead.
I'm gonna be repetitive, but I'll say it again. The Grove Dev team has proven several times now that they know what they are doing. They are one of incredibly few devs out there that you can trust they will deliver on their promises. The game hasn't got an update in a year because that's how they work. Instead of having small inconsistent updates every month like everyone, they prefer to make a huge one once a year or so, it's always been like that. And they are reworking it because the old engine was giving them a lot of troubles, so they changing to the new one so it doesn't give them as many headaches as the actual one.
Sure they are capable devs, but that doesn't mean you can "trust them to deliver on their promises".
Even they are genuine themselves, there are way too many things beyond their control. And The longer it takes, the more variables will be out of control.
You are free to simp for them however you want, but that doesn't mean anything.
This random drop of a Female game is very confusing, like a beloved studio only known for their RPG games suddenly drop a Battle-Royal / Looter-Shooter cuz that's trendy and making more money.
Not to mention their current state on all their projects.
I'm sure they're very nice people, but they haven't proven anything. Of course, they aren't morally obligated to slave away on porn games, but saying that they've shown that they can be trusted to complete a long term project when they've never completed a long term project is just making things up.
Grove will be four years old this month, and Prowler is two. Both games still look like they're setting the framework for the plot with no signs of actual development. Dropping content only every year+, lack of focus, trying to revise things rather than moving forward, adding in mechanics so that they're there even though they're not ready - I'm sorry, but these are very clear signs of an overambitious development.
Again, nothing against them. They're free to drop content at whatever pace they please, and I'll be very happy for it when it comes, but telling people that they'll definitely finish both games is just being dishonest.
Your words have truth in it, but I don't think it warrant the bad faith.
They are new devs with capable hands, making mistakes is how one grow, and they need tons of space / time for growth.
being "ambitious" for their career is a boon, not a bane.
Just temper your expectation, if they indeed finish both games and then some, great!
If not, well, hope we can still see more of them.