Yes, it will still be curated, if you have already submitted your Task. However, the label will be given according to the Sl no of Task(Season 4).

Please refer to the following table:-

If you have completed one or all of the Tasks in Season 3, [Begnner(fixed)], then you will be automatically entitled to the equivalent achievement in Season 4 Beginner[Fixed] as per this table. So no need to perform those tasks again.

I hope it clarifies.

Thank you.