Do i have a right to be upset?

So my partner and I have been together 5 years. Two kids are his step kids ( my bio ) I had before i met him. We have a toddler who is ours.

He is technically my older two kids step dad. Eventually he said he wants to adopt them and get their last name changed to his. Today he went to a financial advisor and put me as the beneficiary and our toddler as the one basically who will get the money if him and I both die. I said what about the other two kids? Then he kind of realized I messed up and kept saying he can change it he wants to change it and split it all 3 of them. If I didn’t even mention them in the conversation then this wouldn’t even be talked about.

I’m upset. My father did this also, only me ( since I was his bio kid ) would get the money but my other siblings who aren’t his ( he raised as step dad ) wasn’t included. It hurt them both very badly as they got older and learned this.

If your coming into my life and my children’s life to be a step parent long term their whole life essentially shouldn’t they also be treated and considered as his kids also not just our toddler? I know he isn’t bio dad but they don’t have a father, he’s their step father. I mean if he wants to discipline and be respected as a father then ?? I mean I am really thrown off. Just feels like my kids aren’t really equal to his own son. Does this make sense? Do I have a right to be upset or am I over thinking and over reacting to this? If I am wrong just let me know because I will learn from it and hopefully understand if I am the problem.