So umm yeah... This happen to me today

It depends on your preferences, if I could choose one of the starters to hatch over and over that would be Chikorita, since the poke games from gba always loved him and want one to power up full with best IV's.

Soi if I were you I would consider myself superlucky.

Imagine hatching three 10 KM eggs to find out all 3 were syther. It is just a coincidence, but things like these happen.

It appears that the only things hatching from 5km eggs are the 3 gen2 startes...so the chance of that happening is not that rare.

I did hatch 3 pichu in a row prior to the event starting...and the odds of that are much rarer due to the number of possibilities at the time.

i just hatched 2 tyrogues yesterday. at least i was able to evolve one into a hitmontop to fill out my dex

I have seen this same behaviour before and I don't think it is coincidence or random luck. I have seen a lot of vids on YT where people get the same mon twice in a row with the same iv. Only thing that changes is weight and height. I think there is some kind of "glitch" but I don't know what triggers it.

It has happened to me two times. I hatched 2 months ago back to back Snorlax, with same movesets and iv's, both eggs came from consecutive pokestops. Also happened to me some months into the game with two poliwags, both the same again.

I don't know if there is some kind of research about this but it is something very interesting indeed.