Horner lost a bit of face when he pushed the Marko instigated De Vries out of the car early, only to have Ricciardo do not have such great results either, despite the grand claims from one test. That weakens your position on driver decisions.
Marko backed that decision (in public) at the time. Marko is now doing what Marko does and sticking the knife in retrospectively. To be honest, I think Horner was right to buy Ricciardo more time. There were signs there that Ricciardo can still unlock his old pace (Mexico '23, Miami sprint, China until Stroll punted him) and that pace was significantly better than anything we've seen from Tsunoda, Perez, De Vries, or Lawson over the last 2 seasons. What Ricciardo has failed to do is show that he can unlock that pace consistently enough, in particular in qualifying and that's marred his chances in races.
Do I actually think Ricciardo ends up with a 2025 Red Bull seat? No, I don't. Either Perez or Lawson will land that seat, depending on which of them does better over the remainder of the season. But in a scenario where both Perez and Lawson stink the place out over the remainder of this season, do I think Horner might go back to Ricciardo as an option? Yes, I do. The question then will be whether Ricciardo is willing to sign a contract with clearly defined performance clauses that could see him ditched at any time in favour of whoever Red Bull can find who they think could do a better job (eg if Hadjar is given the VCARB for 2025 and beats Tsunoda consistently).
The thing for me at the moment is that Red Bull don't have anyone knocking on the door making it impossible for them to refuse entry. They've got Perez who's been terrible (slight pass on that due to them ignoring his feedback on car development, but he's still not been great and does he need to carry some of the blame for not making his feedback impossible to ignore?). They've got Tsunoda who I believe they've already decided is a good benchmark but not good enough for Red Bull. They've got Ricciardo, who they've parked for lack of consistency. They've got Lawson who did a good job filling in last year, but didn't do a good enough job to force his way into the 2024 seat - are we destined to see a repeat of that? Outside F1, they've got Hadjar (some good junior results, but not consistent and currently trying to bottle his way out of the F2 title). They've got Iwasa, I honestly don't know what Red Bull think about his potential (Horner doesn't mention him, Marko does). Lindblad has been talked up, but he needs to show he's got it in F2 first.