Or something like:

use Symfony\Component\Form\Extension\Core\Type\TextType;

$type = TextType::class;

I agree with it in general but I think it feels redundant in short examples such as here or docblocks and is used as is in the core.

I'm fine either way though.

The before and after is not the same thing. And I don't see the point of it.

@Tobion agreed, it misses the new.

Actually we could just remove them, but we have to deprecate them so devs who had the crazy idea to use them as services might be warned to do otherwise.

Telling them to instantiate the class instead can look trivial I agree, but may be needed.
I'm not so sure about both ways.

Waiting for a final call on this, thanks again for the review.

I would simply list the IDs of the deprecated services. Passing them to the form builder should already produce errors as the builder is expecting a string.

Right we should above all avoid to add confusion about that.

So actually it does not really miss the new even if it's not the "same" thing, it is the way to do it now.

I think we should keep it like this.

Maybe just be more accurate:

You should use the fully-qualified name instead of a form type
instead of instantiate it.

I think we shouldn't even mention that. Let's keep it simple like this:

3.1:

The ... services are deprecated and will be removed in 4.0.

4.0:

The ... services have been removed.

Because all the other stuff about instantiating form type classes etc. is already handled in the upgrade docs for 2.8 and 3.0.

Good 👍

Breaking the sentence in the middle looks weird, what about

The following form types registered as services are deprecated since 3.1 and will be removed in 4.0; use their fully-qualified class name instead:

I am still not convinced that it is necessary to add the "use their fully-qualified class name instead" part here (passing the form type instance retrieved from the container already doesn't work).

I think writing "The following services are deprecated since 3.1 and will be removed in 4.0:" is sufficient.

Done. I've first went for @xabbuh suggestion but it was to weird to have just the list.

Since this is the upgrade file and might be relevant to ones getting deprecation notices, so a minimum of "what and what to do instead" makes sense IMHO so I used @fabpot's.

It's now accorded to the framework bundle changelog. Final call ?