This hides a truth: not all parks are gazetted for the same reasons. Setting up a non permanent antenna may be an issue if you step on a hard to see critically endangered wildflower whilst pegging out a dipole leg. That could be considered bringing SOTA into disrepute. In other parks, SOTA may not be an issue.
I’d listen to the ranger and as they’ve been nice and cooperative, a bit of consideration back from all of us will go a long way to helping the situation change. I’d say you’ve done exactly the right thing.