Forgot to say:

I could then release a patch which I'm set up for where I add some extra hard DLC

I don't think this is a good idea unless you're popular enough already, because:

but then the damage will have already been done and people will have been bored with the release and moved on.

Most people who download indie games never play them for more than few hours and uninstall them once they finish (or worse, one they become boring.)... releasing a DLC for a game already uninstalled won't help you.

If you released it on popular platform like steam. The "1st day reviews" will decide the fate of your game (and sometimes even your fate).

as far as I know people don't give Negative reviews for a difficulty they don't like, they give it for fake difficulty, bad design, unresponsive controls, and theme/gameplay that doesn't suit each other.