So, let's say RC eventually comes around to the idea. I'm assuming that by "the process of closing the rifts", Thor means the making of new Gates, with RC as the divine caster. This brings two problems to my mind:

1- The Gates still exist, and so does the Ritual, perpetuating the risk of the Gates being used against the gods (specially if RC double-crosses TDO while doing it, without the god ever giving up on his Plan).

2- New rifts will still appear "in a few thousand years or so". RC is unlikely to still be alive by then, and again, if they don't convince TDO to give up on his Plan, someone will have to pull out the same "convince a high priest to betray his god to patch up reality" with the new "Redcloak", who will serve a TDO who is wiser against the shceme, no less.

So, what Thor just proposed is a temporary stopgap at most, it's just buying time, they'll still need to somehow convince TDO to play ball with the other pantheons (and the other pantheons to accept it).