Not quite if you guys have experienced this, but some of my eggs have shown some glitchy behaviour recently when they’re about to hatch.
I had a 2km egg hatch without an animation last week, and now today had a 5km egg hatch about 5 minutes after the egg “converted” into the pokemon (egg removed and showed pokemon in storage).
Can’t say I’ve seen the no animation glitch but the appearance in the Poke Storage before you have it hatch is nothing new.
My wifes first Snorlax was an example way back December last year. She’d just caught Dratini and went to her collection to collection to do some culling and there was a Snorlax in there before the Dratini.
A few minutes later after catching another 2 Pokemon the egg hatch animation comes up and you guessed it Snorlax. She checked straight away and there was no second Snorlax.
Yes but it has been with the hatches. I have only hatched mankey out of my 15 5ks in the last week, one of them was perfect IV. Event 2ks were ranged but mainly mareep and 10ks were 5 miltank.
Hmm interesting, maybe because I’ve been watching my eggs more closely during this recent event 
The animation is only for entertainment. Once you’ve finished incubating the egg, the Pokémon is in your storage, so if you happen to go to the storage before the animation plays it will be there. The animation can only begin if you’re on the map screen, so if you’re walking around sorting your Pokémon when the egg finishes you may see what you’ve hatched before the actual animations.