This page is our investigation of cross-play feature in game called EA FC 26. We also want to mention that - we always put manual efforts to find the precise, valid, and what is more important official information about different game features without using AI.
Yes, EA FC 26 supports cross-play, but separately for new and past gen. Players on PlayStation 5, Xbox X|S, and PC (via Steam and Epic Games Store) can play together.

Owners of PlayStation 4 and Xbox One can only play with each other, so they cannot play with players on next-gen consoles or PC.

For players on Nintendo Switch and Nintendo Switch 2, cross-play is not available.

Information about cross-play in EA FC 26 was taken from the official website, and you can check it by following this link.
Games can have different cross-play combinations, for example the game can have cross-play between PC, Playstation 5, Xbox X|S, but not between old generations like: Xbox One, Playstation 4, PC. To avoid any misinterpretations, we group them into so called "cross-play variations".
Any store inside the cross-play variation have a cross-play only with a store in the SAME variation. We also want to notice, that we put into variation not platform, but store + platform. That is required because some games, for example, can have cross-play between a Playstation 5 and Steam, but not Playstation 5 and Epic Games.