Oh my bad, apparently its a fairly common rumor that was debunked. There's one former Stalker developer at Battlestate but that's it.I've played all Stalker games several times and this game is not like it at all.
I also do not see the 'inspired' bit.
Chernobylite is a Stalker inspired game.
I can only speculate that the rumor started due to the similar looking dilapidated Russian industrial environment (less the monsters and anomalies etc..), factions and weapons but who knows. Not even sure where I heard it from, but clearly the rumor was common enough that they had to make a post about it