i suspect a few things though i could be wrong or i could be right:
1) that "brother scare" is aware of the pirates and their listeners in this band (go where the fish go)
2) that "brother scare" successfully lobbied the FCC in more way$ than one (money is the root of change)
3) that "brother scare" reads these forums (inspiration is key)
4) this may be just the beginning (expect more SWBC in this band)
yes there are MARS operations on and around 6915KHZ that are very frequently active during the day on the east cost but as its been observed before, they simply switch frequencies (using their emailed charts) when they receive interference, MARS operations have enough frequencies at their disposal just like COTHEN ALE/VOICE operations do in the USA and COTHEN has ALE/SSB VOICE operations in the 7Mhz SWBC band.
if MARS operates within +/- 5 Khz of 6915 and complains enough to the FCC, the FCC may make WRMI change their frequency (just like they did to WBCQ) but times change, so do importance and needs, and i suspect that this new 24/7 SWBC at 6915 is here to stay.
i believe it is likely possible the motive behind this (FCC) is to cause "disruption" to the well known popular frequency of 6925 though i expect the audio bandwidth of 6915 not to be greater than 5Khz each side band, reducing your SDR receive filter to 4/4.5Khz AM (or using ECSS AM USB) will significantly reduce the 5Khz co-channel heterodyne, although if the signal from 6915 is quite strong, there will be some splatter beyond 5Khz that cannot be alleviated regardless of filters/notches used.