Let's clear up this misconception.
All pilots transferring to AA from Envoy begining with the July 2017 classes fall under the part of the contract called Protected Pilots. Protected Pilots and anyone junior to them (including today's new hires) do not get any longevity benefits. When you flow to AA now you get a job, that's it.

Worked at Envoy for 7 years? Thank you. You will start at with 0 years time of service for vacation accrual, retirement, sick, travel, etc...

Did you use ZED tickets while you were at Envoy? We'll you'll have to wait the 6-12months to use them again.

401k? 0% company contribution for the first 12 months, not fully vested for 7 years.

The 824 group who you are referring to were the last to receive these benefits.