I think there's room (both physically and in the budget) for both the Playland and your C, D, E trifecta.
I think the capacity crisis is far worse than it was in the past. It's not just the 1 ride that is closing. It's potentially several shows as well. The BLT even in its stripped down version was still a good 30 to 45 mins depending on when you arrived and how long you needed to wait for the next show to begin at the water tank. If they really close Indy and LMA those were huge people eating shows that absorbed crowds for up to an hour depending on how early people arrived to get good seats. They also closed AI recently. When you combine the shows closing with the removal of BLT you are potentially removing up to 3 hours of guest time. This was a park that some had already started calling a half day park. Regular visitors may have been skipping those shows for years, but the average guest was still going. Now that they have 3 extra hours to kill they will be looking to repeat something like GMR, Star Tours or even ToT that has reasonable lines to fill their time or they will leave the park unhappy.
The park is shifting its focus from a working movie studio with a focus on longer shows and attractions to one based on Disney owned IPs. That's a positive step since the movie studio thing was pretty much dead anyway, but without the time eating studio themed attractions they need to offer guests more to do. Adding 2 or 3 rides isn't going to cut it unless they are really long rides. Realistically, they at least need to double the ride count. The budget is big, but not big enought to build 6 new D/E tickets. There will need to be a mix of B/C ticket rides thrown in too. They won't be the reason to visit the park, but they will provide a fun way to spend some time in between riding the headliners. If they add 3 new E/D tickets (2 Pixar and 1 SW) plus 4 or 5 B/C tickets (3 to 4 Pixar and 1 SW) that puts us at 12 or 13 rides with 8 in the D/E range and 4 or 5 in the B/C range. Plus the LM and Beauty and the Beast shows and a few other exhibits or minor attractions. If you include Fantasmic as the nighttime entertainment that's getting us into the range of a complete 1 day park.