You don’t have to read all those links.
This statement is ample:
Selective pinching of the terminal buds to increase branching can continue up until about the first week of August (later in the South). Pinching or shearing must stop while there is still enough of the growing season left to allow the plants to set flower buds for the next spring’s show. Late pruning will take away the flower buds for the following year.
In formal garden, like some Japanese gardens, evergreen azaleas are often sheared to smooth rounded shapes. This is fine and gives results that are pleasing to many people, but, as we indicated earlier, shearing must stop in time for the plants to set flower buds.
In summary, the first rule of pruning is to select the right varieties in the first place and plant them where they’ll do what you want without a lot of pruning. There are hundreds of varieties to choose from, dwarf, medium and tall, in many colors, blooming early and late. The second rule is to stop pruning while there is still time for the plant to set flower buds for the next year: around the first of August in the Mid-Atlantic region, and late August in the South. Third, don’t leave stubs when pruning larger branches; cut them off flush with another branch.