Much of it depends on what sort of bikes you are working on. For instance, I've noticed a lot of multitools now come with a torx bit, but none of my bikes use them.

Bottom brackets and crankarm attachments seem to have gone proprietary over the last several decades. I actually had a harder time finding a wrench and pin spanner for a traditional BB on an older bike.

The only general purpose tools I can think of offhand that seems new is the fourth hand tool (cable stretcher).

Pricier than the old third hand tool that simply held the pads against the rim, but once I figured out how to use it, I loved it.

I would suggest on the more proprietary items, to just buy them as needed. Once you replace all the missing tools, your first set will turn up. That's what happened to me.