100 probes will be gone after a handful of systems...
It seems like you won't need to scan every body with probes, or even most, unless you want to.
You'll get the equivalent data/credits/"discovered by" that you currently get from the Detailed Surface Scanner by tracking down and zooming in on a planet with regular Discovery Scanner from anywhere in the system. So if you're looking for credits, materials lists, or discovery credit, you can get everything you get currently without using probes. You don't even need to carry a DSS now if you just want those things.
You only need the DSS and probes if you want to find specific sites of interest on the surface (or if you choose to collect the new "First Scanned by" credits) and the regular Discovery Scan will tell you if there's anything worth using the probes for.