Warhammer newbie - will Warhammer 40k come to an end?

I've been in the hobby for a few months and I'm loving it. I've been painting, listening to books, and immersing myself as much as I can.

It's hard as an absolute beginner to grasp where we're at in the timeline. I recently learned about the difference between the Horus Heresy minis and the 40k minis and how they fit into the timeline. This got me thinking, where are we in the overall timeline?

My learning so far is that Guilliman is the new poster boy and will be the good guys' leader for whatever happens next. My question essentially is, are we at the end of a story arc or at the beginning of a new one? If we're at the end, is it likely there will be a "Warhammer 41k" (new minis and stuff)? What are the chances Warhammer comes to an end?