Re: No they havent.
While I don't know about the 1st two or the 5th of your numbered points and they sound plausible I take issue with 3rd and 4th
3rd - it would not need all operators or planes to be fitted with the system - the airport would maintain all the old systems alongside the new just as they do now with the decades old ILS and the current precision approach systems, also right now not all airports or aircraft have precision landing systems and there are procedures to ensure the pilots know if and when they can use a precision landing system or have to use a Mk1 eyeball.
4th - it would not require the approval of all aircraft manufactures, just one - as above a precision landing system is optional - if there is demand from operators then it is a commercial decision for the manufacturer to make.
But I agree that the EU acted disgracefully over Galileo, but then the whole Brexit was (and still is) a predictable cluster fuck by both sides driven more by posturing, prejudice and hurt feelings than any considered desire for the best outcome. Fucking politicians.