Old seasons added Eras

Eras 

Older seasons returned to the modern game like 2K with Eras 

Added in the future FC26

16/17 Golden era

14/15 Ronaldo Messi Era

11/12 Ronaldo Messi Era 

07/08 Ronaldo Messi Era 

04/05 Ronaldinho Era

The players would then have their ratings and teams  would have theirs

Newer players would appear as you progress. 
If I start in 14/15 I would see a young Rashford the next season 

players with their old faces and realistic

ronaldo with noodle hair in 16/17 

And Messi with short hair in 14/15

All old kits 

with maybe returning or new leagues

Players with a play style + will get an additional Playstyle plus in career mode if they are above 90 or turned 90. 
Use the old kits in different seasons like 07/08 kits in 16/17

Player models and be able choose how the player looks choose Ronaldo 07/08 face for the 25/26 season or Neymar 11/12 for 16/17

Please EA and Thanks to anyone who likes this post