CoolBreeze2106
No need to call the HO.
When COA is abolished (whenever that will be) you will simply have the freedom to give notice of marriage without having to seek permission of the Secretary of State.
The COA scheme was introduced as one 'tool' to combat sham marriages. But was written in a way that discriminated against religious beliefs (other than Anglican)
If I were in your position, I would personally make the application for COA (I think no fee is being charged, and it will not be refused anyway)
With everything going on right now in government there is no way of knowing when it will be taken out of legislation.
Unless, you can find a way to marry in an Anglican church! (also not without it's twists and turns)