I was confused by the question, but it seems that my going to the twitter thread helped for me to look through what seems to be being asked... which is not really that great of a question if you think about it.
In other words, history does not really provide any meaningful guarantees, but as Adam Back seems to be proclaiming, the 200-week moving average is a very strong level of support that allows a bit of sanity in regards to a likely bottom if the BTC price ever does go down and also a bottom in terms of likeliness that if we get prices at or below the 200-week moving average, it is not too likely that the BTC prices are going to stay there for very long...and/or not too likely that such BTC prices will go lower (again, no guarantees).
For me, I have probably ONLY been seriously considering the importance of the 200-week moving average for right around 2 years, and maybe even less than 2 years.. .. .Oh gosh.. it's almost as if I need to go back and review some of my own evolution of thinking about the topic. For sure, the 200-week moving average can be helpful in a lot of areas of our bitcoin journeys, but we also need to keep our eyes on the prize, because even greedy folks can end up screwing aspects of their own bitcoin journey because they use such 200-week moving average in ways in which they might end up trying to trade in accordance with it in major ways in which they fail/refuse to adequately keep a decent stock of BTC in order to be prepared for UPpity, in case it happens.
Recently, I have been considering devising some kind of a chart or table that helps me to better consider the 200-week moving average for some members who might consider themselves to either be getting close to fuck you status or already in fuck you status... and the underlying premise would be to allow ongoing liquidations of BTC on a regular basis but also to attempt to adjust such liquidations in light of how close or how far above the 200-week average the BTC price might be... so for example, right now we are just a bit above 2x above the 200-week moving average, so likely any kind of normal withdrawal rate between 4% to 10% may well be maintained (using the 200-week moving average price as the calculation reference to arrive at limitations). Historically, the BTC spot price has gotten more than 15x above the 200-week moving average, and for sure when the BTC price is even more than 5x above the 200-week moving average there could be some signs that either the BTC price is a bit over heated or maybe it is O.K. to shave off higher percentages of profits.. while at the same time appreciating that this should not be any kind of all or nothing kind of game in which large amounts of BTC are shaved off - even though I can appreciate how that tactic could be profitable especially if the spot price is getting above 15x the 200-week moving average (if that ever happens again?).
So, if you have not yet gotten to fuck you status, and you are considering whether the spot BTC price might be in a good spot to invest into BTC BIGGEDly, I doubt that the history of the 200-week moving average is going to really help you that much in terms of attempting to time possible lump sum investments to be more profitable (to the extent that is even a reasonable/prudent goal).
This linked website seems to be amongst the best for looking at the history of BTC spot price (and even zooming in on any specific date) in comparison to the 200-week moving average.. and even providing colors to help to easily pinpoint how much higher BTC spot price is as compared to the 200-week moving average on any date going back to the beginning of 2012.
By the way, since BTC price has historically had a tendency to ongoingly stay above the 200-week moving average, the 200-week moving average has continued to go up.. even during decently long periods, such as 2015 in which BTC's spot price was nearly touching the 200-week moving average for close to 10 months.. Even the 200-week moving average moved up slowly for that whole year - starting out at something like $192 and ending at $244 and continuing going up.... albeit relatively slowly.
Again, no guarantees but it seems much stronger to be considering your BTC holdings by using such base and foundational price rather than getting too preoccupied with spot price - even though for sure we know that spot price does play some decent role if you are not just blindly HODLing but instead considering either buying or selling some BTC in light of your own personal particulars.