I'd think it would ferment.
I don't know about if the PH (vinegar) would mess things up,but I'd think you could adjust that with baking soda or?
My point is,I don't think the ferment depends on anything but the sugars etc. in the peppers.
You use a starter for fermentation anyway.
Sour dough starter has alcohol that turned to vinegar in it.
Thats where the sour taste comes from.
All sour Dough starter needs to keep active is more food to get it bubbling again.
Ph stops some yeasts from growing I don't know about the stuff you use to ferment peppers,yogurt type stuff.
I've only made Sour dough starter , wine and beer.
I've had gal. jars of peppers in vinegar ferment when I left them out on the counter...
Might be because it had a fruit/cider/wine Vinegar in it,I don't know.
My Fridge went out one time and my pickled peppers started to ferment.
They had other veggies in the jars though too - carrots,onion,garlic and spices.
I used a lot more vinegar than 50% in my peppers most times.
I used almost straight vinegar because as I ate them I added new peppers to the jug.
It never emptied in years.