No I don't believe it, Messi want to join Inter Miami because he get more interesting offer e.g. receiving share of Adidas and Apple, also we're know if FIFA is always favor to Messi since he won few controversial Ballon d'Or. Since he win the world cup and his performance is still looks outstanding, this give him a high chance to win the next Ballon d'Or. If he join Saudi Arabia team, FIFA will not favor on Messi and this could make Mbappe or Haaland will win.
LOL... I don't think that he is that interested in either stocks or the Ballon d'Or. His main issue was that family members were opposed to staying in Saudi Arabia for extended periods.
https://www.goal.com/en-in/news/lionel-messi-wife-antonela-roccuzzo-hesitant-move-middle-east/bltfaf171e72e65c50cHis wife (Antonela Roccuzzo) made it clear that she is not open to relocating to middle-east. Messi had the option of leaving the family behind in Europe and moving to Saudi, but in the end he chose against it. Roccuzzo was concerned that their three young children may not get adequate care in middle east.