I’m certain they’re telling you to specifically use RIAA phono equalization - which is of course the defaut for virtually all phono stages, now. But I agree the choice of wording was poor. If they were using ANY other curve to cut that record, they would have mentioned it by name.
Even with the correct EQ, older records can sometimes tend towards sharp / bright treble. The playback components of those days weren’t treble / HF assault-cannons like a lot of hifi gear is now - they were usually mixing for softer, much more laid back speakers (e.g. paper cone tweeters).
Hagerman makes a reaonably priced "Achiver" phono stage, with widely adjustable Turnover & Cut knobs for totally custom phono EQ dialing. Not sure I’ll ever have enough records that would need it, though. The other alternative would be something like a Schiit Loki, for a fully adjustable analog EQ - it’s not a phono EQ, but might be better for overall fine tuning (e.g. softening sharp treble). Or (god forbid) digital EQ :)