The whole point of stopping radio coaching is because drivers are the ones that are suppose to be driving the cars, not the teams in the pits.
I understand why they would want to limit the communication. I think maybe why I'm struggling with the idea so much is that, to me, it seems like F1 is so far down the rabbit hole, that this seems like a rather strange attempt to dig itself out.
My dad is the one who got me into F1 and racing in general as a kid. He's since turned into a bit of a hippy, and has completely fallen out of touch with motorsport, but we still have conversations about it on a certain level. I'm trying to picture the conversation between him and I where I'm trying to explain this concept of pre-approved radio communication, and I can't picture him having any reaction other than drawing a completely blank face, pausing, and then bursting out into hysterical laughter.
I can almost gaurentee he would say something along the lines of "So why not get rid of the damn radio all together...saves weight no?"
To which I woild reply "I don't know...probably for safety reasons?" At which point he would scoff (he grew up in Europe in the 50s and 60s, watching the gnarliest of the gnarly...he's not too keen on safety culture

) and change the subject.
Not sure what that has to do with anything...I'm rambling now, sorry.
They can certainly try, but they are limited to approved subjects. It would be very hard to make the case that "the recipe calls for three eggs" refers to an approved subject. And they can't really play dumb, since why are they talking about their dinner plans in the middle of a race? In terms of penalising it, the stewards won't have any choice but to penalise any communication that isn't explicitly linked to approved subjects because they can't take the chance that the teams are trying to circumvent the ban. Sure, it presumes guilt, but the teams can't afford to risk it. And they will have to go along with it to show that they are serious about responding to fans.
There is already a partial ban in effect - this was actually something that the FIA wanted to introduce last year, but went for a scaled-back version. At the moment, teams cannot discuss the performance of other drivers, such as where a rival is stronger than them in qualifying. There haven't been any problems - aside from the occasional message of "How far back is Driver X? / I can't tell you that, mate" - so far, so this is nothing new to the teams and drivers.
Ya, I suppose that could work, hadn't thought of it from the "presumed guilty" approach. I guess we'll have to wait until Belgium to see.
Also, I wasn't aware of the current restrictions

Like I said, I'm a casual. Can I come watch F1 at your place? You really know your stuff 👍