Getting to a point of over-accumulation does tend to result in a lot of options that were not otherwise available during the time that accumulation was still taking place, and a person likely gets from 5 BTC to 6 BTC after a decent amount of hard struggles.. and sure there sometimes could come reassessments that end up allowing conclusions that 5 BTC is enough - and then recognizing that he has 6 BTC..
In regards to your suggestion that the extra BTC could serve as an emergency fund is not completely off point, since whenever anything is extra there are options with it - yet still it does not tend to be good practices to have your emergency fund denominated in something other than your own local currency... which truly having BTC as part of your emergency fund could lead to selling some of them at price points that are not very convenient.
But yeah even having 6 BTC rather than 5 BTC could cause the HODLer to feel comfortable to begin some kind of a
sustainable withdrawal strategy - especially since he has extra BTC. Even with a 6% withdrawal rate, there could be 0.025 to 0.03 BTC withdrawn every month... and it would take quite a while (several years) to deplete the amount down to 5 BTC.
I agree that bitcoin certainly should not be an emergency fund, as you may need to sell it in low prices.
I also see bitcoin as an insurance, in case things don't go well in the global economy or locally here in Brazil.
In this sense, bitcoin can save me in possible emergencies in the Brazilian economy. but this is different from an emergency fund