I'm sceptical... they've gone on some really extravagant holidays in the past especially for their anniversary...to do it on the same date / around it seems like something Sophia has mentioned in the past as something she would hate.
An €850 helicopter flight seems to be minor for these two's income & I'd imagine her boyf has had time to save / plan ahead. She probably saw someone else do it on TikTok / insta & said to him she'd love to do that one day as a passing comment.
If she does get engaged I think she will go quiet for a few days before posting pics from when it happened - black n white pic / video of her hand in Brian's showing the ring or him with his arm around her & hand over his face / his head cut off or just his chin kissing her head or a pic he took of her sobbing while holding her hand up to show the ring.
Wonder how Cinzia feels, their life's were parallel until she broke up with her last ex & Sophia moved in with her boyfriend. Now Sophia's life has excelled in comparison especially if she ends up engaged.