No idea what it will, or "should" correct down to. You could say that if everything starts normalizing, including interest rates, bonds, real inflation, real economic growth, etc., then it should revert to some sort of historically mean P/E.
There are many forces at work, not just policy, but individual and generational considerations, and foreign interests.
It is unquestionable that algos are ruling the trading day, and that (along with mechanisms like limit-down like we saw last night) lends a considerable consistency to the short-term market moves, at least downward; however, socially we are due for medium-term and possibly even long-term cyclical events, the swing of the electoral pendulum being one such medium cycle IMO.
Of critical importance will be whether Americans will be essentially forced into equity and bond markets through the effective elimination of comparable alternative investment vehicles; this does, and would, provide a significant buffering effect, especially regarding progressive withdrawals from and drawdowns of, tax-advantaged retirement accounts.
Also, in the near-medium term, fiddling with the money supply via QE is likely to affect the markets. Gotta have some meaningful physical and productive assets because price inflation will manifest, and will affect the markets.
I therefore doubt that we will see 13k, and that if we do, it won't last for very long. Realistically I could see maybe 14.5-15k sustained for a period, after a bounce down to maybe 14k, after which I think a normal rise will attend a period of "normal" inflation, if not real growth.
What a bunch of b.s., right? Just like all the other "experts" out there.