NGUI components get Transforms changed to RectTransforms after upgrading the project

How to reproduce it:
1. Open the project "case_1346253.zip" from Google Drive link
2. Load Assets > "Scenes" > "MGUI_Issue" Scene
3. Observe the text field

Expected result: Warnings doesn't appear in the Console window
Actual result: Warnings appears in the Console window:
"Creating missing RectTransform component for UILabel in Label."
"Creating missing RectTransform component for UIButton in ButtonEdit."

Reproducible with: 2020.3.0f1, 2020.3.14f1, 2021.1.16f1, 2021.2.0b5, 2022.1.0a2
Not reproducible with: 2020.2.0a21
Could not test with: 2019.4.29f1

Notes:

• Only reproducible with the user's project
• UGUI asset is used from: https://assetstore.unity.com/packages/tools/gui/ngui-next-gen-ui-2413