With how awful the vans are I personally can't see them keeping up the DRT service for that much longer.. to be fair to them 5 out of the 6 sprint solos are operating services today (obviously 2 of them are covering for the dreadful Merc vans though so that isn't helping them!)
Thing is there's a couple of problems with that. The depot at Loughborough can't handle loads and loads of vehicles (I'd imagine it can get quite cosy overnight with 40-odd vehicles) so it would certainly be tight and not very ideal if they were to keep another 2/3 vehicles there. You mention them keeping 175, 107 and 108, which they have, as from what I've heard depots are only allowed a certain number of vehicles before they are no longer allowed to operate any more (presumably enforced by management at LM). 175, 107 and 108 should be on the town runners a lot more now skylink has received new vehicles, hopefully with 346 and 347 also appearing frequently! However now it seems a few of the spare Optares are in a spot of bother at the moment, in particular 478, 502 and 822, which have all been off for a few days now, along with 715 which appears to have been having issues over the past few days. Basically all I'm saying is, 107 and 108 have indirectly replaced 831 and 832 (which let's be honest, weren't the most reliable anyway!) which can be used as a little stop gap before the Yutongs arrive later this year (and hopefully will make the towns a bit more reliable)!