Jared Padalecki will indeed be reuniting with Eric Kripke for The Boys Season 5.
The actor who played Sam Winchester for Kripke on Supernatural confirmed the news in a recent interview while discussing the cancellation of his series, Walker, on The CW.
Kripke also brought Jensen Ackles onto The Boys to play Soldier, Boy, Jim Beaver is featured, and the new season sees Jeffrey Dean Morgan playing a role.

āIām going to go play in Kripkeās newest playgroundā
Last month saw Eric KripkeĀ state he wants a reunion with Jared PadaleckiĀ in Season 5, and that is exactly what is happening. Jared Padalecki told Variety the following:
Well, Iāll say this: Kripke and I texted today. Itās not been written yet, but I think he was saying [the final season] doesnāt even film until 2025. So yeah, Iām going to go play in Kripkeās newest playground. I had a great time the first time around, so Iām sure Iāll have a great time here again. I love the show. I think itās hilarious and exciting. But you were asking what my plans for the future were ā and I love Jensen and Eric Kripke. Obviously, Iāll be indebted to [Kripke] and entangled with him forever. I met my wife because of him. I was Sam Winchester because of him. āSupernaturalā happened because of him. So working with him on a show that I enjoy, Iām like, āYeah, when do I fly out?ā But I donāt think we would film until at least January.Ā

Why was Walker canceled?
Regarding what happened with Walker, no surprise, it was canceled following Nexstar taking over The CW who wants to go the cheap route with its content:
I feel like The CW that I was a part of last year is not The CW that I was a part of under [former chairman and CEO] Mark Pedowitz for that entire, almost 20-year stretch. Theyāre just changing the network around, where itās not really going to be a TV network as much as itās going to be, āHereās something fun for an hour that youāll never watch again, but hopefully you watch it. And itās cheap!ā And I hate to say that, but Iām just being honest. I mean, fuck it. They canāt fire me again. Iām just being brutally honest. I think it felt to me like they were looking for really easy, cheap content that they could fill up time with.
New episodes of The Boys air Thursdays on Amazon Prime Video.
