Interesting one here - I requested a new investor card back in December and then switched on this labs feature when it first became available.
I haven’t gone around updating my details but just now I’ve had a notification that my Spotify subscription has been billed. I’ve logged into my account to check and once you skip past a few warnings about them not being able to take payment I can see that they have my new card details in there.
So two observations with this - it looks like this WILL work even if you switch the feature on after requesting a card, and it looks like with Spotify at least, they only detect the new card after trying and failing to take payment.
I’ve got Dropbox and Netflix due out soon so I’ll see what happens with them.
Edit: I just remembered that I had to update Netflix manually last month.
As for Dropbox, I’ve just logged into my account and I can see from the last 4 digits that they already have my new card details so it looks like that works too!