Pretty lame that they didn't add this to all Ludicrous vehicles IMO and not something I would have expected would be made exclusive intentionally.
The problem was that they are using Ludicrous+ as both the Acceleration Mode and the Easter Egg, and they made this change in 2019 some time (sorry, don't remember the version).
But originally what way it worked was this
Accelerations Modes went up as far as Ludicrous. Then there was this phrase that said "Max Battery" and that did just that, it would heat up the battery to the proper temperature. Beyond telling you how long it was going to take to get to the proper temperature, nothing else was apparent in terms of visuals.
Then as Brooks indicated in that video, Tesla released the Ludicrous+ Easter egg, which took the "Max Battery" to the next level. This gave you the "I want my Mommy" feature along with the new instrument cluster visuals (temperatures, and new telemetry data).
Then in some weird moment, Tesla confused everyone, by changing "Max Battery" and renaming it as a new acceleration mode called "Ludicrous+" which technically is still Max Battery while still offering the Ludicrous+ Easter Egg "I Want My Mommy". and this confused everyone.
In summary,
The P100D has both the Ludicrous+ Acceleration Mode and Ludicrous+ Easter Egg with "I want my Mommy"
The P90D has the Ludicrous+ or Insane+ Acceleration Mode but no Ludicrous+ Easter Egg with "I want my Mommy"
The P85D has the Ludicrous+ or Insane+ Acceleration Mode but no Ludicrous+ Easter Egg with "I want my Mommy"
The temperature and telemetry only appears if you can engage the Ludicrous+ Easter Egg with "I want my Mommy".
I just wishes they kept the Max Battery as the Acceleration Mode name vs. Ludicrous+ and researched Ludicrous+ as the Easter Egg name. Would have saved a LOT of confusion.
Note: Max Battery now gives you access to Launch Mode on a P100D, and it's easier to engage (less pedal mashing) with the most recent firmware.