I understand your perspective, but I don't think I'd handle it that way if I were Elias in the context of this team (not a contender). Zimmermann could get a shot and so could the rule V guys. I would only promote Baumann for that role if the other guys clearly don't belong.
I know he'll be 31, but I'd still value that year with a high-upside arm.
Honestly, we don't have much more information and the lost season last year makes it even worse. He'll play at 19-years old and with so many high draft picks ahead of him needing playing time between Low-A and High-A, I suspect he will start the year in the GCL League.
With no NY-Penn League anymore, the Orioles will only have one rookie league team in the GCL Orioles so playing time will be at a premium. The 1st year player draft next year has been moved back to July 11-13 so that allows for some more playing time for guys.
Now, the rub here is that the Orioles could choose to start Maikol Hernandez in the GCL if they think he's advanced enough to handle that. That could move Placencia to second base if the Orioles are high enough on him to bring him over to the states which considering the options right now, makes sense that they will.
I really don't think service time games should ever be much of a concern for a pitcher. If they're ready, get them up here. Of course, that also assumes that winning games at the MLB level is important you, which is clearly not the case for the 2021 Orioles.
As others have mentioned I would think Elias would want Baumann to see time at AAA regardless of service time issues. I think you see him pitch there for about half the season (depending on what happens with the minors) and then brought up in the 2nd half if he's effective.