Continue reading:"The statement reads a bit vague as to what will happen to Rocket League on Steam after it arrives on the Epic Games Store later this year. The wording suggests that while it may not be available on Steam, Rocket League would still be supported. "
So nothing has really been confirmed or changed. The concern remains.
We reached out to Epic Games and Psyonix who have offered this clarification: "We are continuing to sell Rocket League on Steam, and have not announced plans to stop selling the game there." An Epic spokesperson added, "Rocket League remains available for new purchasers on Steam, and long-term plans will be announced in the future."
While it's not "we are definitely going to keep selling Rocket League on Steam indefinitely", it is an improvement on the original statement, which did heavily imply that Rocket League was going to be removed from Steam as soon as it launches on the Epic Games Store (and, judging by Segey's twitter, was most likely the plan).
So, we shall see. Either way, if you're interested in playing Rocket League on Linux, I'd still say nab the game sharpish.