There are some threads on a few other forums tonight about Sky giving Family/HD pack customers some free Sports content.

Here and re-reported Here.

If this is true does it mean F1 coming out of old HD mix since they already get full F1 Coverage or are they just giving it to all Family pack customers and therefore there is no need to keep the HD mix?

Reading a it further the 10 races are the ones you can already watch on BBC. The OP doesn't really clarify F1HD status.