Of course, it's the last time anyone in the squad played competitive rugby, it's the best indication we've got.
Are you saying form during the last season should be completely irrelevant to Lancaster's decisions?
Why should it be relevant?
Form, by definition, is of the present. Last season's in the past. If you're saying last season is the best indication we have of what form they're in, then I'd have to say a) No it isn't and b) If it really is, so what? It's such a poor indicator that it's worthless, even if it's the best indicator.
I mean, they've gone on holiday, they've done a gruelling pre-season, they've spent... I forget how long in the England environment, and they haven't played competitive rugby in three months or so. The idea that they're in the same form now as they were at the end of the season just doesn't make sense. It makes about as much sense as basing Premiership final predictions on which teams were doing well during the Six Nations.
In any case, as this stage, the best indication there is to how the players are performing at the moment is how they're doing in training. That may have some limitations, but it is of the present.
So, yeah, I think form last season should be absolutely irrelevant. It is about who is going to contribute most to England in the next couple of months; not who was contributing most to their clubs in the past.