My connections at RedHat say nothing has changed for them, and that RedHat is not IBM.

But Jim leaving does make it look less likely that IBM will be turning into RedHat anytime soon.

From what I'm told RedHat continues operating as an independent business unit under IBM.

Edit: full disclosure; I too am considering RedHat, as I'd like to resume full-time work on systemd/journald in the future and there aren't exactly many places employing people to work on upstream systemd. So I may be biased in wanting to believe the above is true, grain of salt and all.