I was in Overwatch with all my soldiers not revealed yet. A Sectoid and an Advent soldier walked in and saw me, Overwatch triggered as the aliens had revealed my group for the first time. One soldier hit the Advent soldier and killed him while they were scrambling then the sectoid stopped where he was and fired and critically hit and kill one of my soldiers.

Is this normal behavior from Xcom2 Wotc? Or it this something ABA adds.

I only use ABA and ABC for game play changes NO LW2 or anything

Just curious because i don't remember aliens being able to take offensive actions on reveal like that.