In standard American English, masculine is the default gender when the subject is unknown. So using "him" is proper. Using "them" as a singular pronoun is jarring to the ears.

Third-person singular they has a long tradition in English. It may not be as familiar to you, but it's nothing new.

https://en.wikipedia.org/wiki/Singular_they

I was not aware of this, I've mostly heard "they"/"them". I take "he" to be an awareness or assumption of the gender, and find it quite uncomfortable to hear with regards to an industry with such a strong gender imbalance.

No. It's actually a fading usage. The current pronouns when not assuming gender are they/them.