Batch renaming, removing -2 from from file name, is it possible?

What would make it very easy is a simple find/change file rename feature, but unlike Adobe Bridge and many other file management applications, Lightroom Classic cannot do this. That is why you need workarounds like hoping Preserved Filename will get you there, or using a third-party plug-in.

I believe this discussion is going nowhere, because it is unclear what the exact question is. You got files with '-2' at the end, because you imported them into a folder that already contained files with the same name. That is clear. But now the question is what you want to do next. Do you intend to first remove these older files and then rename the '-2' files? That should work and using 'Preserved file name' (which means 'the old file name', really) would be the way to do it. Or do you believe that some plugin might be able to do what Lightroom cannot do because your OS does not allow it, namely remove the '-2' from the file names while the old files with the same name are still present in the same folder? That is impossible.

If you DID NOT rename on import you can use Presereved Filename to name it to the original name.  (This MAY work if you did rename on import.  I did not try that)

Otherwise you can use the Search and Replace Transfer plugin by John Beardsworth

http://lightroomsolutions.com/complex-file-renaming-in-lightroom-thanks-to-search-and-replace/