how does McFadden getting activated mean Jaylon is not?
it is not one or the other.
also is McFadden going on the roster or just practicing under the NFI rules?
He can practice with the team for 21 days but not be on the active roster I believe
That is from the IR, not the PUP or NFI list. Only 1 player per year can be activated from IR.
PUP and NFI are not the same status. There is an 11 week window for any player to be removed from PUP/NFI. That window closes tomorrow. If the player doesn't start practicing he is done for the season. If he does start practicing the team has 21 days to put him on the 53 man roster or he reverts back to PUP for the remained of the season.
"A player who finishes the preseason still on the PUP list can then be placed on the regular-season PUP list. Such players must sit out the first six weeks of the regular season. At that point, teams have a five-week window in which to allow the player to begin practicing; from the day the player begins practicing, teams have an additional 21-day window in which to decide whether to activate the player to the 53-man roster. If either of those deadlines pass, the player must remain on the PUP list for the remainder of the season."
https://en.wikipedia.org/wiki/Physically_unable_to_perform
It doesn't look like they will practice him, but there is nothing stopping them from elevating Hannah, Smith, and McFadden all to practicing before tomorrow's deadline according to league rules (other than injuring them further obviously since they will then have to participate in practice).