If those bitcoin miners were still holding bitcoins for a long time, they would have made huge profits by now. This is all also deducted from the costs they have to pay for mining, for example electricity costs, equipment, etc.
Of course, if they hold their Bitcoin since few years ago, they must get huge profits in this bullrun season. However, it is true that the miners must sell some of their Bitcoin for electric fees and other things. It is normal because it should be paid first, it is the capital of the miners. If I were a miner, I also do this.
most of these miners have participated in several bitcoin halvings, so they understand the habits of the 4 year cycle when the halving occurs
Indeed. The miners must understand the 4 years cycle. They know how long to keep the Bitcoin for taking profits. However, I'm not sure if all the miners will be quite patient to wait for some years.