Quick rumour, take with a pinch of salt.
Apparently Fissler reported that Gloucester will give a new contract to one of JSD or Sharples, but not both.
Both are out of contract, and it fits in with the need to redirect resources to the front 5, especially when May, JSD and Sharples may be too much to spend on wings. Also, contract negotiations are going ahead at Glos, as Twelvetrees has already had an extension announced, so the time frame fits in.
I think Glos can find a use for all three. May can play some 13/15, JSD can play 13, and rotation is needed anyway.
If the rumour is true, I cannot really fathom why Glos would even consider re-signing Sharples at the expense of JSD. Makes me kind of doubt the rumour to begin with.