This scenario contains at least two concepts: (1) declining length of future working lifetime and (2) increasing ratio of assets to goal.
Focussing on the first, there's some theory that says you should keep your mix of stocks and fixed income the same over time (It diversifies stock exposure across time and maintains an even percentage risk level, both of which are optimal.) However, you should the count the present value of your expected future earned income as fixed income. This first concept alone might explain a big part of your planned shift to fixed income.
Your risk aversion at retirement would explain your asset mix at 25 to 30 years out.
If you keep working, you'll expect to go from 25 x expenses to 35 x pretty fast, so your shift to bonds looks to be happening faster than your future income stream will be capitalized. Perhaps a kink in your utility around 25 x expenses would explain your rapid shift. This is the second concept.
In your shoes, I'd have a higher stock allocation at retirement, as you'll still have a long time horizon then. You probably gain no safety below 60-75% stocks. You may even have a higher risk of not keeping up with inflation; and, you lose a lot on average. Keep in mind that you'll still have social security of some kind at that point, which is like a bond (with some political risk).
Faced with having substantially more than needed to retire, rather than put a lot in bonds, I'd sooner keep the stock allocation high, lower my spending by a small amount the first few years, and expect to have much more later. This isn't so much a question of temperament, but simply based on the historical statistics that suggest bonds are not very competitive with stocks over longer periods, so they don't make sense even for fairly risk averse persons.
Finally, another concept: it probably doesn't make sense to drop your mix out of stocks in the short period before retirement (as opposed to right after). Before you pull the trigger and retire, you have an extra sort of security in the option value of keeping working.