I don’t understand why you have to sell your btc just to buy back again btc? Maybe if you sell your altcoins so you can purchase bitcoin, that would be a very smart idea. But selling off your bitcoin so you can buy bitcoin again, not actually a good idea for me. Instead, just do the DCA or wait for a price correction and accumulate more bitcoin to add on your portfolio, that way you will have massive profits with bitcoin in time.
I believe he wants to take profit now that price is above $110k, then buy more during bear market, that would not be a bad strategy unless Bitcoin doesn't fall below the price he sold when bear market starts. Let assumed he sold when price was still above $120k and he holds the Fiat until 2026 when comes the bear season and Bitcoin dips to $50k, he can buy more by then. If it works like that for him, then it's not a bad strategy but Bitcoin can be unpredictable sometimes, such that price might not dip to the price he expected.