I hope U2 or BE do make a connection available as so many people used the BA service to connect in Gatwick with the Caribbean flights or BA and VS, not just as a point to point service.
Most of which are gone by mid morning. LGW was de-hubbed and now gets by on point to point with some feed from the regions. However the second and third daily flights would have next to no long haul to feed.
The second issue is that the B737-400 is not ideal, it's too big for frequency, and they didn't replace the smaller B737-300/500s. Removing the night stopping MAN-LGW killed what was left.
flybe and GIP at LGW are in dispute over charges, MAN-LGW would not do well under the current charging regime.