RG59 might be fine unless it is a very long run.
I have an original RG59 run in my condo from thirty years ago. If I use it I can still view the same digital content (and run MoCA on it) as with the RG6 runs I put in. But there is certainly more signal loss with the RG59 which will come into play with a longer run or a weak channel.
TiVo Mini x4
Roamio Basic OTA
39TB unRAID1--53TB unRAID2--36TB unRAID3