Well, with all the delays in deliveries, I can imagine that they don't want to announce an opening date until they are certain, that they can make it.
The amount of work necessary for the reimaginaning - at least, as we expect it, is really not that much. Yes, you have to replace/remodel the whole straight track of the launch and brakes, + add new electronics for the LSM and do some remodeling of the station to accomodate the new trains, but this is easily doable within 7 months. There is no need to pour new foundations, there is no track to be mounted in larger heights, the supports should also be able to remain in place.
You can set up most of the electronics necessary while you change/modify the existing track, and simply lay cables to the LSMs later.
Other parks can build whole coasters within 7 months, so the LSM upgrade is certainly within the realm of possibility.
However, I can't rule out a 2024 opening, but why would you start now, if you don't expect everything to be delivered within a few months?