Go for it!!
Planatus is commonly referred to in Australia as Planes, and in North America as a sycamore. They can be traced back to 100 million years ago!! This is the number 1 tree planted in parks in North America.
Sycamores don't require anything out of the ordinary as far as pH, but leaves that drop from trees rarely contribute to pH. It would require the raw wood of only a few trees like pine, redwood and some cedars to contribute acid to the soil.
It's actually the pitch in pines that create the acidity, and that takes the fresh wood in contact with soil, or a leak out of the bark straight into the soil to make it acidic.
I know people think adding pine needles increases acidity, but it's not really the case. They are carbonaceous and need nitrogen to break down, so they might compete with whatever plants they are on the soil with for the nitrogen (so just add extra). And redwood has preservative chemicals in the wood only, so that during the process of breaking down in the soil it creates a slow growth situation. But once broken down is a great soil amendment. I've always grown up with redwoods, and have lots of experience watching what they do. Their bark chips can create some issues with annuals.
I can find you cites about this, I just don't have them at hand just now. But I post to lots of gardening boards, and we've had this discussed and researched many times.
So you've got a fabulous source of mulch, how lucky!!! Go for it!!!
"Life flows on within you and without you"...George Harrison
Coastal California, USA, Mediterranean climate - no summer rain, a little frost mid-winter