They are meaningful. But the party choosing to set the result aside for good cause is hardly a coup.
What if information came to light that Trump in fact was on Putin's payroll? I mean, irrefutable evidence of it. Would the GOP be forced to nominate him at the upcoming convention? No, of course not.
If in this case the Dem party decides that Biden is not competent to be POTUS for the next four year,s that his decline is too imminent and substantial, they ought to be able to set aside the primary results, too.
Neither would be a good look. But as is, it seems to me that Biden has next to no chance to win and that it his own ego standing in the way. Reminds me a bit of RBG hanging on for too long. The old guard -- across the board (see e.g. McConnell) have to learn to step aside when the stepping is good.