@Easty Tab A8 is certainly eligible for quarterly security updates, however may take a bit longer as it considered to be a lower tier Tablet. I do not yet see a scheduled date for One UI 4.0 https://9to5google.com/2022/07/01/samsung-android-12-update-rollout/
I do not work for Samsung or make Samsung Products but provide independent advice and valuable contributions.
My Device- S21 Ultra 5G ( SM-998B/DS ) CSC= BTU , 12GB/256GB
One Ui 4.0,Android 12 Official Version.