Huffington Post has an interview with Bob Ducsay, editor for The Last Jedi, in which they asked him about Ackbar's death:
“That was how it was designed. It’s interesting that you mentioned it, because I watched the film last night and I thought, hmmm, maybe that’s too incidental.
Not exactly crying himself to sleep about it, but at least it's an acknowledgement of a mistake that left longtime fans feeling like Ackbar's death was yet another cold example of "letting the past die." It's maybe reminiscent of how fans felt when Chewbacca walked past Leia after Han's death in The Force Awakens.
Meanwhile, The Verge tells us not to shed a tear for the useless character. After all, he was only in one film for a few minutes, leaving his character to be fleshed out by the endless morass of the old Expanded Universe.
More than anything, mourning over Ackbar’s death in the The Last Jedi feels like mourning over fan-made canon. It’s mourning over hypotheticals and a childhood nostalgia that remembers Ackbar as something bigger and better developed than he was.
While I wouldn't go so far as this article does to marginalize Ackbar, I do agree with the author that Admiral Holdo was better served handling the suicide mission, and that her story served a greater purpose for the survivors, especially Poe. That said, and without the benefit of knowing the Episode IX plot, I think it would have been even better to have Leia handle the lightspeed maneuver, as a heroic sendoff for Carrie Fisher. Holdo would then have been set up to take the reins of the Resistance for IX.
In any case, let us all raise our glasses to Grand Admiral Gial Ackbar, Hero of the Republic, the Rebellion, and the Resistance. Dilly Dilly!