No code-share but plenty of interline partners from LGW, including BA, BD, VS, EK, SQ plus many other non-UK carriers. There is nothing stopping people from using the BE onward connections although granted the majority of these you could probably fly direct from LBA to.
Some passengers choose to travel into LGW and hop over to LHR. If the route can work in places like NCL where they still have another (current) London connection I am sure it will work for LBA.....just a little bit of faith??