Olton,
I'm not standing up for the post by FFHKG (I'm not sure what the post was trying to achieve to be honest), but, the Thomson online brochure, and travel shops agents seem to show/say that MAN-SFB will be 4 weekly all winter, not just one month.
LGW-SFB will be 2 weekly all winter with BHX-SFB having an extended season into November and early March re-start.