I don't think a rearrangement of tiers would help.
As I wrote in another thread...
Normally folks making their single tier 1 FP+ would be split between Soarin' and TT, with many selecting a Soarin' FP+ planning to do a rope drop for TT. In addition, folks unable to get a FP+ for either or could only snag a tier 1 FP+ later in the day may also plan to do rope drop which would again be split between TT and Soarin'. This is the reason why within 30 minutes of rope drop both Soarin' and TT have long wait times.
With Soarin' down for a while, I foresee TT FP+ becoming as rare as MK 7DMT FP+ and IllumiNations FP+ becoming like a MK Wishes FP+. (As a side note, I'll know it's the apocalypse if I see FP+ for Living With The Land run out.)
Since the new Frozen ride will not be ready until possibly May-June 2016, there is no other ride to take the place of Soarin'. If anything, I'd expect wait times for Mission: Space to possibly be higher due to increased demand for something to ride at EPCOT.
Long story short, while Soarin' is down anyone even remotely interested in doing TT should definitely try to get a TT FP+. Wait times for TT during this period are sure to be brutal.