I think it depends tbh, if I were you with only 3 embers I wouldn't bother, but there is always a risk that fish have picked something up/the stress of the move will make them sick, and make your current embers sick too. My tank got ich this week from fish from a different shop, I wish I had quarantined them, though it seems very treatable.
I have had mixed experiences with the fish from WoW. I've bought some chili rasboras and rice fish from them with no problems at all. I've also bought some otos from there last Autumn and didn't realise until I got home that one had a white mark on its face. Over the next week all 5 died and some developed these white marks that ate away at the flesh. 😭 I went at the end of the day, was tired and forgot to ask more questions about the fish like when they got them in, I assume they were quite new so I kinda blame myself cos I know this is a common oto problem. Luckily none of my original otos died and it didn't seem to spread in the tank (I took out all the new fish once I realised).
Their tetras and gourami always look really healthy and perky, I think it is a great place to get them from. I buy fish from there and definitely will continue to, especially as they often have in some nice unusual species. I probs will quarantine going forward after this ich experience cos I don't like how guilty I feel when the fish I already have get sick.