I think BLE is only required for the initial compromise (extracting the pairing key). After that the attack can be performed over classic BT, and can impersonate either part (headphones or phone) to the other.
It’s still very targeted and sophisticated, so no reason to panic unless you have reasons to think someone with the resources could target you.
Regarding the attacks, they go way beyond eavesdropping calls, since BT headphones usually have access to contacts and smart assistants, that you can use to extract a lot more information

Every frickin day… at least once, I read a post’s title and start looking around for clues that it’s not real… My mind goes: “is it the onion? Is it April’s fools again already? This can’t be true…”

1. ‘No’ is already the default, that’s why you get the banners, to trick you into opting in. There are a couple of filters that you can enable in uBlock Origin to get rid of (most of) the banners.

I’ve seen them in Germany, but between relatively small cities and towns.
Not Just Bikes made a video about Trams not long ago.