bug(tree): deprecated tree control is not removed in v21

[JelleBruisten]

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

20

Description

Hey,

I noticed that tree control and related api's are marked as breaking change in v21, these are still exported. I'm wondering if this is intended ( and angular team does decide to support this treeControl for longer ) or an oversight?

Reproduction

Expected Behavior

removed in v21

Actual Behavior

not removed in v21

Environment

• Angular:
• CDK/Material:
• Browser(s):
• Operating System (e.g. Windows, macOS, Ubuntu):

[crisbeto]

It means that we can remove it from v21 onwards, but we haven't gotten around to it yet.