No, this is about trade and the EU will not intentionally handicap its member states to punish an ex-member. The UK and EU can reach a deal that is acceptable to both, because the EU will act in its own self interest and want to keep a major trading partner on its border on good terms.
The UK will not receive all the benefits of membership, but the UK does not want all of them, so being a member will remain attractive to existing members.
The EU will not try to flex its muscles, because it will end up destroying the EU.