bug(cdk-virtual-scroll-viewport): Virtual scroll keeps elements in memory on destruction

[tibi0010]

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

19.2.15

Description

Items wrapped in cdk-virtual-scroll-viewport persists in memory even after the destruction of the virtual scroll element.

Reproduction

StackBlitz link: https://acasmhd5.stackblitz.io
Steps to reproduce:

1. Click toggle button a couple of times
2. Create a memory snapshot
3. Check elements in the memory snapshot

Expected Behavior

cdk-virtual-scroll-viewport does a cleanup on destruction, does not retain elements.

Actual Behavior

cdk-virtual-scroll-viewport keep elements in memory even after destruction.

Environment

• Angular: 20.2.0
• CDK/Material: 20.2.0
• Browser(s): Google Chrome 141.0.7390.108, Firefox 146.0.1
• Operating System (e.g. Windows, macOS, Ubuntu): Windows 11