Ok.
You can do the same at the other end for the 600k over 65's dying. Overall it gives a net gain per year for remain of between 350-400k, which wipes out the 1.3m majority in less than 4 years.
Actually its 90% so that is 540k of those 90% voted 486k of those 60% voted leave (291k) 40% voted remain (194k). A loss of 97k of leave.
So you would actually only gain 100k votes per year and that is assuming that voters don't become more conservative with age, and you seem to evade when challenged on that.
You estimates of net loss of brexit votes due to death is conservative, due to:
1. You've used % age of death only for men, who tend to die younger - when you add in women your proportion dying at age 60+ is more like 95%.
2. And actually you can go lower, given that the 55-64 category (and even the 45-54) are also disproportionately leave voting (57% and 56% respectively) - that further adds to the net loss of leave voters due to death. There are tiny numbers of deaths in the remain majority age categories of 18-44.
And you also have to add in the net gain to remain at the other end - currently there are 780k 17 year olds who will turn 18 and be eligible to vote - using the same approach - 64% of those would vote (just as the brexit turnout figures indicate) - in other words 500k and of those 73% would vote remain, meaning net gain to remain of 220-230k per year.
I haven't ignored your notion of people getting more conservative with age, and I read your link with interest - but I hardly see this as relevant to the current discussions on brexit and demographic shifts not over coming decades but over the coming few years - perhaps to 2021. There are a number of points to make:
First this is about identifying with the conservative party, not about brexit - you cannot extrapolate one to the other.
Secondly, as the author points out a perceived shift with age, may in fact be merely that it’s not a person’s age that is important, but rather which generation they belong to. So you have to actually track the cohort. And the article (or rather it's data) allows you to do this.
So from the graph - in 1979 41% of 30 year olds identified as conservative. In 2010 those same people are now 70 - and now 39% identify as conservative. So there has been a reduction in their 'conservatism', defined in the manner of the study, in that 40 year period. Likewise elsewhere - in 1987 44% of 40 year olds identified as conservative, fast forward with the same cohort, and in 1997 just 31% of 50 year olds identified as conservative - those are the same people remember.
So there is very limited evidence for this effect (as the author concludes) over a period of decades - much less so over a period of just a few years.