Shimmy, I am not sure how useful my experience will be for you, but I will pass it on in case it helps.
Ds1 was born with hypospadias (urethra not at the end of his penis and an incomplete foreskin). He had an operation to put this right when he was 5 and the surgeon used the foreskin to reconstruct the urethra, make an opening at the end and drew his foreskin round so it looked complete. Since then we have moved and another surgeon has looked at ds1's penis and tutted loudly, said he would never do the operation like that, ds1's foreskin is too tight, he should have been circumcised, etc.
All very distressing given that ds3 also has hypospadias and will be operated on by this man who will make a completely different job of him to his brother. Ds1 is also on a time limit: he has to practice moving his foreskin back and forth in the bath and loosen it by this June or the surgeon will want to opearte on him (basically circumcising him).
BUT, at the same time as we got this message from the second surgeon moreorless implying the foreskin should be loose by now (ds1 is 9 now BTW), we also know from talking to our original surgeon that tight foreskins are still normal for this age. This is because ds2 (no hypospadias but with a tight foreskin) has difficulty moving his and we asked our original surgeon about it and he said they can remain tight without any medical concern until the boy is around 14.
So, we have 2 different medical opinions, but certainly one would suggest that your son is fine for now.