I’m inclined to think the intended effect should be "all units don’t ready during the next upkeep. But either way - for the current game it doesn’t make a difference, so I’m going to post a turn assuming both Immortals do not ready during my upkeep.
But I’m really curious how this will be ruled!
PS: thank you for providing me with this possible line for future situations in this tournament. TD Immortal into Elephant with now! was something which hasn’t been on my radar before this awesome turn of yours 
XCAFS23 round 3 part 1 P2T8
P1 [Finesse]/Feral/Present vs. P2 [Feral]/Present/Discipline
Link to all relevant rule changes
StartingHand Workers
STARTING HAND
Timely Messenger (1/1)
Wither
Older Brother (2/2)
Bloom
Granfalloon Flagbearer (2/2)
Temporal Distortion
Feral Strike
WORKERS
Fruit Ninja (2/2)
Granfalloon Flagbearer (2/2)
Bloom
Spark
Older Brother (2/2)
Wither
Tenderfoot (1/2)
NextHand
Behind the Ferns
Research & Development
Timely Messenger (1/1)
Brick Thief (2/1)
Feral Strike
Discard
Feral Strike
Helpful Turtle (1/2)
Temporal Distortion
Temporal Distortion
Research & Development
Tech 0 card(s)
Get Paid + scavenger - ($13)
Hyperion attacks Geiger, takes 3, I draw
Hyperion from hand kills Geiger, takes 3, I draw - ($8)
boosted feral strike, search & bring to play: tric & giga - ($0)
tric pings tower once & kills elephant
old tric breaks tower, takes 1, base to 18
cal breaks tech 2, base to 16
Float ($0)
Discard 4, draw 5
Board Info:
In Patrol:
Squad Leader: Gigadon (8/8)
Elite:
Scavenger: Tricycloid (3/3)
Technician:
Lookout:
In Play:
- Cal (4/5, lvl5)
- Tricycloid (3/2)
- Hyperion (4/2)
- Immortal (5/5)
- Immortal (5/5)
- Hyperion (4/2)
Buildings:
Base HP: 20
Economy Info:
Cards:
- Hand: 5
- Deck: 0
- Disc: 5
Gold:
- Gold: 0
- Workers: 12
Thoughts
okay it takes one turn longer than expected, but it’s still game, even if I don’t draw value from my two Hyperions