No. The Founders were already preparing to take on the Federation in ~70 years time and without Odo, there was no dissenting perspective to their (apparently) species wide xenophobia and paranoia.
I don't recall this, is it canon?
The Founders mention that they weren't expecting the Federation for around another 70 years in The Search, Part II.
As for the Founders being paranoid xenophobes, just watch any episode featuring them after The Search and before the series finale.