LOL it would be funny if that glitch would cause the money rock to turn into a egg rock, like when you hit it with your shovel eggs will pop out! That would be kind of cool actually...
I experimented by intentionally leaving four rocks in placements I didn't mind to see if they'd stick. None of them did. They were just gone the next day.
However, just so people are aware, you're not stuck with your rocks. You can get rid of them by starting an alt and using the new villager's house to take out the rocks.
I've heard of it happening. Had a friend on the NOA testing team who vouched that it was a real problem they noted, but wasn't fixed before release. The easiest fix was simply to break them all before you finish playing for the end of the day.
Also, those rocks are programmed to function as real rocks if they do glitch, meaning you can't put a house over them. It can be a game breaking glitch, but an easily avoidable one.