Totally agreed, there is unlikely to be any "Red Nosed" Airbus.
It does not make sense for a LoCo to have a mixed fleet for any number of reasons.
To the Thai feeder rumour I can also add one doing the rounds about many senior NAS management seen visiting Vueling on occasions ,& a possible link/tie-in with them to feed traffic into a Spanish long-haul hub. Anyone familiar with T's &C's in Vueling will not rejoice at this news.
The visit I am assured is apparently fact, the rest of course is merely speculation.