But even if until 2025, will they have to pay retroactively for 2023-2024 I assume?
It depends on the financial year of the company. If the company has a Jan-Dec financial year, corporate tax only applies from Jan 2024.
Then by the end of September 2025, their declaration and payment of the corporate income tax for Jan-Dec 2024 would be due.
For companies with a financial year July-June, corporate income tax would apply from July 2023, and then corporate tax would again be due 9 months after July 2024 (too lazy to do the math).
At least that's how I understood it.