Regarding a gray Rick w/ an un-aging Michonne & Carl, I'm almost thinking that it's a dream or vision of Rick's - it's how he *wants* things to be - that "tomorrow" that he wants to start living.
And maybe why Rick is aged & Michonne & Carl aren't aged is because they don't make it into this "future" - so, in his vision, he sees them as they were.
And the close-up shot of his face where he looks shell-shocked & his eyes are all red-rimmed from crying is the actual future. And it all began w/ that scene on the flatbed truck where they rallied the people for an All Out War.
But I also was just wishing he would have shot Negan when he had the chance (he had a clear shot!) & I can't figure out why he just left him there.
Also, on last night's Talking Dead, something was mentioned about Gimple now "helping" w/ Fear the Walking Dead.