True. The ones you can't edit are the ones that belong to licenced teams, as shown in Bold below (from the Exhibition Match setup screen after all stadia have been unlocked:
1. Santiago Bernabeu, Madrid [Spain]
2. Nou Camp, Barcelona [Spain]
3. Estadio Riazor, La Coruna [Spain]
4. Estadio Mestella, Valencia [Spain]
5. Old Trafford, Manchester [England]
6. Highbury, London [England]
7. Stamford Bridge, London [England]
8. Anfield, Liverpool [England]
9. St. James' Park, Newcastle [England]
10. Stade Louis II, Monaco [France]
11. Parc des Princes, Paris [France]
12. Stade Velodrome, Marseille [France]
13. San Siro, Milan [Italy]
14. Stadio Delle Alpi, Turin [Italy]
15. Stadio Olimpico, Rome [Italy]
16. Ennio Tardini, Parma [Italy]
17. Westfalenstadion, Dortmund [Germany]
18. Olympiastadion, Berlin [Germany]
19. Scüco Arena, Bielefeld [Germany]
20. Amsterdam Arena, Amsterdam [Holland]
21. Stadion Feijenoord "De Kuip", Rotterdam [Holland]
22. Rasunda Stadion, Stockholm [Holland]
23. Vodacom Park Stadium, Bloemfontein [Africa]
24. Newlands Stadium, Cape Town [South Africa]
25. La Bombonera, Buenos Aires [Argentina]
26. Estadio National / Giants Stadium, Santiago [South America]
27. Busan Asiad Main Stadium
28. Seoul World Cup Stadium
29. Sapporo Dome
30. Niigata "Big Swan" Stadium
31. Kashima Soccer Stadium
32. Nissan Stadium
33. Nagai Stadium, Osaka
34. Tokyo National Stadium
35. Oita Stadium
36. Saitama Stadium
37. Club House
38. Random
Not sure why you'd want to edit these as they are correct but you can't yet. You should be able to once a WE10 option file editor is available on pc.