Yeah, that's a very fair point, and also the financiers just want to get the most back out of their investment, don't really care how the promotion affects people's experience in the theater, so they would probably go with the "better safe than sorry" promotional philosophy. Which is why I'll be very surprised if we get all the way to opening night without seeing Superman in a trailer, in some capacity.
What could work out for all parties is if they had a good emotional scene (something that shows a good part of Clark as a person) between Superman and Lois that took place before his death, that Lois is reminiscing about. Start the trailer out with that, then show a close up of Lois being taken out of her thoughts maybe Perry White is calling her name, or she's holding something of Clark's. Then the trailer goes forward with the focus on the other characters
I think it would be good in the trailer to build up that World Without A Superman feel, that shows how he has inspired people. That was one of my favorite story arcs as a kid (I had all three TPBs, Death, World Without, and Return), because it did a good job of showing you the importance of Superman, and the way he impacted and inspired ordinary people. So why not use the trailers to emphasize that point?