Typically, no. Since many of the TVs in today's RVs don't have a QAM tuner you can use that coax connector to hook to the cable box you rent from the campground (and then hook the box'es HDMI output to the HDMI cable Thor provides back to the TV).
Maybe: That box doesn't boost the TV signal, it simply sends 12 VDC to the amplifier contained in the antenna. At some point that 12 VDC is "injected" into the coax leading to the antenna. Sometimes it is done at that box with a coax cable, other times it is done closer to the antenna with an "injector" coax connector.