Is it really needed though? Personally I feel that if the current subclasses get implented in a good way, there is enough diversity. And it would be yet another thing Larian had to take into account when balancing the game, and let's be honest here, game balance is not really their strong suite.
This plus if you give out a feat at level 1 there is even a less chance people will take a feat at level 4 as opposed to ASI.
Take my Half Drow Cleric, Kaedyn. At level 4, I give him the Weapon Master feat so he can use the Sword of Justice. Fits with his Tyrite character. If I got a free feat, I'd have him welding Long swords, Heavy Crossbows, Greatswords, etc., right at level 1. Then, at level 4, ASI. No other feat appeals to me for him, and he'd be a WAY tougher Cleric throughout the entire EA.
Yeah. No. It's unbalanced to hand out free feats. A cleric should not be tougher than a fighter at level 1 in regards to dealing damage. Ya gotta leave some room for characters to grow and learn new things.