I'd love to see Thiem beat Nadal at the French. However, if past is prologue, his chances aren't high:Why? Federer still HAS the lead and is still playing. People are assuming Nadal wins another slam and whilst that is certainly a possibility, it's not a certainty with Djokovic still around plus several players are actually now stepping up. Thiem is still a threat to Nadal at the french and i don't see Nadal winning another Wimbledon. That's ignoring the biggest threat to the players now, injury and fatigue due to age which could hit any of them at any time.
2019: Nadal beat Thiem 6-3 5-7 6-1 6-1. [Game score 23-12].
2018: Nadal beat Thiem 6-4 6-3 6-2. [Game score 18-9].
2017: Nadal beat Thiem 6-3 6-4 6-0. [Game score 18-7].
2014: Nadal beat Thiem 6-2 6-2 6-3. [Game score 18-7].
13 sets played there and Thiem got to 5-5 ONCE. He did, admittedly, end up winning that set.