That assumes that hey move over band 26 or replace it by band 12 or b71 (if you have a compatible phone) they move over band 25 spectrum and possibly add another RRH and move over B41 panels/RRHs or replace them with T-Mobile compatible panels/RRHs with b41/n41 MMIMO and give you access to them via a SIM swap or something. Roaming is not working real well right now since you have to lose coverage before it will switch you over.
With network upgrades being 5G centric as well as Sprint subs being left off the T-Mo network unless no other Sprint signal can be found, will result in an even smaller footprint. Yes this is assuming that majority of the redundant sites torn down being that of Sprint's network. Until there is consistent network sharing, Sprint subs will be weaned off the network through 5G device upgrades or through leaving due to shrinking service.
Not sure I follow you? If the site is "redundant" meaning there is a T-Mobile site there too or very near by, why would it cause problems? We will all be on one network soon, ... some sooner than others.