I certainly think it's risky (it goes without saying that it is also wrong). With Venezuela, it seemed you had a regime and populace that, fundamentally, were maybe mildly disapproving of US, but the regime was, in their hearts, pretty comfortable with corrupt arrangements and the Trump administration fits right in with those arrangements. Even an interview with one of the folks the regime unjustly imprisoned seemed at peace with the regime being intact, with a fairly "this sort of corruption is just the way the world works" attitude toward the whole thing.
The Cuban people have endured decades of the US working to actively screw them over, and may be less 'pragmatic' about the best way forward even if it means accepting wrong being done and may be more ideologically engaged to recipricate, even if it is likely not going to be a 'win', but at least make the US hurt for what they do.
Yes, that's a very very basic negotiation strategy, anyone who has even heard of a car being sold knows that super basic thing.
However the Greenland situation is more like going to Walmart and demanding they give you a PS5 for free, and then Walmart saying "you can have it for $599" and then declaring "victory" because you never expected it for free, but you got the price you wanted. Except $599 is the list price and you didn't have to every make a stink about wanting it for free.
Trump was never that 'great' at this sort of thing, but his old age has eroded his ability to have any sort of filter that would facilitate even trying to play things close to the vest. What he says is what he thinks, more plainly than ever.