They’re both wrong. Someone in your parish has “male-pronoun-phobia.” It’s
Blessed is He who comes in the name of the Lord.
You’ll have people all over this thread in a couple of hours advising you to read Redemptionis Sacramentum, highlight the relevant passages, bring them to the priest, and when the priest doesn’t give you satisfaction, go to the Bishop.
Do you sing or say this part of the Mass (Sanctus)? If you sing it, the difference is probably due to a new musical setting. If you say it, there’s somebody who made a conscious decision, and you should approach this person and kindly ask for clarification. You might be surprised at the answer you get. Who knows what they’re thinking.
Is this the only thing they do wrong? It seems that this kind of thing would not be the only thing, since people who don’t like to refer to God as “He” usually make more than one change. If it’s widespread, it is probably worth addressing. If it’s just the music, you can probably express your preference for a setting that uses the correct words (have one in mind - people here can help you with suggestions) and let it go at that.
Although it is very true that no one has a right to change any part of the Mass, and the people have the right to a properly-celebrated liturgy, you really have to do some strategic thinking. If this is the one and only thing that’s wrong, it might not be strategically advantageous to fight this fight. Once you complain, especially if the people in charge are well-entrenched in their ideology, you will be labeled as a troublemaker and largely ignored. There are matters much more weighty than this that might come up later, and you don’t want to take yourself out of the fight now when you might be needed later for something really big. You want your reputation intact when it’s time to address a really big problem, like something that would invalidate the Mass altogether.
If it turns out that now is not the time to make a fuss, say the right words to yourself during the Mass, make an act of reparation for the liturgical abuse, and pray for the people who are behind it.
Betsy