The Nordic hamstring curl itself is ancient but relatively new in preventive physiotherapy. Relatively new in such a field means like 10 years tho. Still bar Micah Richards I have never seen a football player perform it. One has to keep in mind that a lot of the conditioning routines that are used in English (and German for that matter) top flight football are very outdated. Just look at the pre-match warm up stretching routines they do. Those are rather traditional to say the least. We used to do the very same routines in our kids' footy matches 20 years ago. A lot of those stretches are proven to be ineffective or even harmful esp the way they warm up their hip flexors and mobilize their spines.
Hence, I do think that clubs all over Europe would benefit from more progressive methods that sadly arrive in Europe with a bit of time lag. US sports trainers and therapists appear to be a lot more advanced. That being said, the Nordic curl is a very advanced exercise even for elite athletes. I have been doing fitness and strength training for 10 years now and can not yet do a full ROM Nordic after months of practice. Amidst all the travelling and regular training it will take a dedicated and concerted effort from the conditioning staff to work him through a progression. Usually off-season as @MoroccanBlue said would be the perfect opportunity to learn the movement. So whilst even the Nordic can not protect you from injury through trauma it shold prevent all those strains Pulisic suffers without impact. So, I do think that Pulisic is unlikely to have mastered the Nordic yet but he would profit greatly from it.