Lore is a bit tricky, in that you don't want it so rigid that it stifles creativity - but at the same time, you need to keep a handle on it because limitations are what provide definition. A great deal of creativity tends come itself from finding novel solutions around existing limitations. You need to be able to strike that balance in expanding upon, or selectively retconning lore in a way that grows the brand and increases internal consistency, but at the same time not making it such an amorphous mess that brand is meaningless.
Bringing cats back... sure, I'd say that's fine. They were never extinct until shortly before FO2's time anyhow - both wild and domestic types, and the only people to mention their extinction are isolated individuals on the West Coast. Unless the famine that lead to their being hunted for food was global (which strains credibility in itself) - there may well be populations elsewhere in America. The power armor changes... eh, yeah. I can even buy into that. I'm not happy with the Power Core change, but it's to facilitate gameplay mechanics. Same reason why Power Armor in FO3/NV required training, when it didn't in previous games. That's pushing it, but ok... it serves a greater purpose. Not a fan of it being literally everywhere on the East Coast either... but without a BoS chapter (or similar organization) operating in the area to fleece them all up and keep them out of waster hands, sure - it makes some sense they'd be more available in Boston than in DC or the West Coast.
But Kid in a Fridge? Cabot House/Mojave alien cities? Pre-War Jet? This shit is just asinine, and neither facilitates world building, compliments game mechanics, and only serves to damage the brand by destroying lore for little more than a throw-away gag or "cool" (it's not cool) scenario. Obsidian/BiS also put some lore-breaking scenarios and quests into FO 1/2/NV... but which were obviously only intended as Easter Eggs, or locked behind an optional "silly things" trait. Nobody serious thought that the Chosen One went back in time to destroy V13's water chip. They didn't try to play them off as serious things happening in this world.