The EU did not compel Apple to have a comercial relationship with Epic. It is Apple who decided that third-party software distributers must comply with certain

The EU did not compel Apple to have a comercial relationship with Epic. It is Apple who decided that third-party software distributers must comply with certain restrictions, and must sign a contract with them. And it was Apple which tried to prevent Epic from signing that contract, and who's now backtracking… before it's forced to do so by the EU.