How to index more than 20k pages in Google?

Question

Google

Sparsed a couple of dozen sites of the same subject, it turned out a little more than 20k "unique" pages (300-600 characters each) for a new site. What is the best way to “bring them out” to the bourgeoisie? Does anyone have any experience in this regard, so that everything does not hang in snot? The domain under this business is defended 10 years.
I plan to break posting for 6-7 years. Everything will be fasting from “different” users, a couple of “live” comments on each page, etc. But how to put such an amount into the main Google index - that's the question)
6 years = 2200 days, that is, 10k pages should be posted per day, 420 per hour, 7 pages per minute.

Answer 1

for a site with a large number in the index, behavioral factors are important, Google checks whether the site is useful in 3-6 months, then the picture will become something like this,
so don’t count on 6-7 years, think about how to give naturalness and that the pages are created by natural users too

Answer 2

Promote your material on all possible platforms, including such foreign social networks as StumbleUpon, Tumblr, Pinterest and LinkedIn.
If it’s not a secret how such a volume became unique, how many years we worked and how we parsed