Hi Mikhail,
I think you have already got the reply in multiple views, I would like to add my view in below words.
I believe your question is not about the S/4 HANA, it seems it is about New GL. And it should be because there is no migration scenario available to activate below functionality once you have migrated from R/3 to S/4 without new GL
1. Document splitting
2. Balance sheet at profit center level
3. Parallel Ledger approach
4. Segment reporting
5. Inclusion of custom fields
If you are not thinking to have these functionality now or in future you can migrate to S/4 HANA, as EC-PCA is untouched in the functionality, means it will update ACDOCA and EC-PCA table for the profit center documents.
Hope this would have given more insight!
Thanks.