There is one reference we can list.
In the memorial, there is a name Roberto da Costa aka Sunspot. This mutant is going to be in an upcoming film, The New Mutants. This refers to the upcoming merge of X-Men and current MCU. I don't have a screenshot at the moment.
From Bookmyshow article,
MCU has always avoided referencing X-Men which might have been due to the fact that the rights were owned by Fox. Now that the Disney-Fox merger is over, we can expect to see more X-Men references, with Avengers: Endgame being the first of many. After Ant-Man returns from the quantum realm five years later, he comes across the Vanishing Memorial that has been set up with names of everyone who had been dusted and scans through them. One of the names is Roberto da Costa aka Sunspot, a mutant who is associated with The New Mutants and X-Force. He is confirmed to be in the New Mutants film coming this August and might be in the upcoming X-Force film with Deadpool too.