Unfortunately I don't think there is any built in function for this. The best you can do, at least in terms of keeping it simple, would be to create a Smart Group capturing any Macs with that pkg in the Waiting Room directory (something like Packages cached by Casper | has | <package name>), then create a policy that uses the Advanced command run function and does something like:
rm -Rfd /Library/Application Support/JAMF/Waiting Room/<package name>
It should only execute on Macs that have that pkg on them and delete only that package. You just need to make sure you use the correct pkg name.
And be sure to have the policy collect new inventory after so it moves the Mac out of that Smart Group.
Another option would be to do a Before script like the above and set it as part of your 10.10.2 caching policy. It should run, delete any instances of the older pkg and then cache the new one.