In the circumstances it does feel like a bit of overriding the older son. I would not, for that reason.
Just a thought. If your husband has a middle name, you could continue the tradition by giving your son his middle name as your son’s middle name (or one of them, if he will have two). Because the older son got your husband’s first name as a middle name.
If you figured something out that was unique yet “consistent” between the brothers (without it being “Son 2.0 New and Improved Version”), it might be a nice way to make the brothers feel connected.
In my part of the world, incorporating family names to younger generations is pretty common. If elder son has some part of a family name and younger son doesn’t, it might make younger son feel left out later on. (That’s just another possible perspective, not necessarily everyone’s or the correct perspective.)
My husband happens to have two middle names, so we gave my kid two middle names, one from each side of our extended family. One of them was the middle name of a great grandparent. Then she got her very own, unique first name. Kid seems pretty happy with it.