Slitherine

Will the Operation Sealion GC be seeing any continuation?

It does, you can import the army into 1943 Eastern Campaign.

I agree it would be nice to invade good ole US, but I do not think they are going down that route.

I'm pretty sure that standard Sealion core won't transfer to 43 East, but Nikki made an adjusted version that does.
I'm not sure whether it changes Sealion or DLC 43, so you should check first.