The following is based on 80 pilots per month being hired at AA. (80 total, not just flow) Historically there has been at least one month per year at AA with zero new hires, typically December, actual hiring numbers may vary but 80 is what both the union and the company think is an accurate number.

New hire seniority: 2400 As per most recent flow plan
Non flowing pilots: 200 As per most recent interactive list

According to the MEC newsblast on 12/7/18 we had a non flow attrition of 205 YTD or about 19 per month. We'll assume this rate remains consistent for the foreseeable future. Because pilots about to flow are significantly less likely to peruse employment outside of flow we'll assume those 19 per month come from the last flow group.

Protected pilots: 29/month -1 month per year for AA training backlog. -2 months for AA training to get through s80/190 retirement training bubble. About 200 pilots remaining in group

200/29 = 7 Months with flow + 3 months of non flow.
10 months * 19/month non attrition flow = 190 pilots

It will take another 10 months for the protected pilots to flow during which time we will lose a total of 390 pilots.

Unprotected pilots: 15/month -1 month for AA training backlog. There are 148 pilots in this group.

148/15= 10 months + 1 month of non flow
11months * 19/month non attrition flow = 209

It will take 11 months for the unprotected pilots to flow during which time we will lose a total of 357 pilots.

Summary for first 2 flow groups: It will be 21 months until the first pilot from the post agreement flow group starts. During this time we will lose about 750 pilots.

New Hires: The remaining pilots will flow at a rate of 5 per month + (Senority list-480)/125. Or about 20 per month.

New hire seniority (2400) - Non flowing pilots (200) - pilots in protected and unprotected flow groups (750) = 1450 pilots left to flow from last flow group.

19 Attrition per month + 18.3 average flow per month (20/month for 11 months out of the year due to AA not hiring in December) =37.3 pilots per month

1,450/37.3 per month = 39 months from start of last flow group + 21 months for first 2 flow groups = 60 months until flow.

So accounting for the various flow group rates, historical attrition, AA not hiring due to both s80/190 retirements and typically not running classes in December it should take about 5 years for a newhire to flow. Add in a year for hiring slowdowns, less attrition the predicted, and other shenanigans. 6 years to flow for a new hire isn't totally outside the realm of possibility. Of course 6 years is a lot longer than the 2-3 months it takes to polish your resume, take your suit to the cleaners, go to a few job fairs, and get yourself a new job half a decade before your peers who wait for flow.