If you’ve got the rattle I would take it in. The rattle happens because the old style hydraulic timing chain tensioners bleed off overnight and allow slack into the timing chain, and the chain whips around inside the timing cover and bangs against the front of the block and back side of the timing cover. All while chiseling off little pieces of aluminum debris and sending it into the oil pan. If the aluminum shavings don’t take it out, the timing system will if they jump time.I do have the cam phaser rattle on start up and have for about 40K miles. Everyone has said the rattle doesn't mean whether they are going to have to be replaced, it is unpredictable.
The new tensioners (released mid 2023) don’t bleed off when the truck sits. The new phasers also don’t bleed off either, and the repair (if done at a Ford dealership) will come with a 100k mile warranty from Ford.
With the cost of an engine replacement (something like $12k on an ecoboost, no clue on a 5.0 coyote), I would do the $4-$5k repair now on my own terms if I could afford it and avoid a surprise down the road.