Frankly, mailing lists were in existance prior to email or computer data processing, as in mailing publications/advertisements/pricelists to a list of subscribers/victims.

We stole their term, and they're stealing it back. Seems fair.

I don't have an OED subscription, but in the free fact sheet, they note "OED's earliest evidence for mailing list is from 1898, in Overland Monthly."

https://www.oed.com/dictionary/mailing-list_n?tab=factsheet

And why would they say "for newsletters AND MAILING LISTS" in their 1-sentence description? You can file a bug report if it's not a mailing list at all.