No, not true. It dehumidifies based on the amount of cooling it does, not whether it does it from continuous duty or on/off cycling. That cooling by itself causes the condensation from the air. I'd like to see a rebuttal to that if you have a source? I worked in HVAC a lifetime ago, still have a cousin that does.
Running constantly to reach some temperature is more efficient energy wise, but does not reduce humidity more, and after a certain point in the duty cycle will wear it out faster.
This is also true for the window units, less efficient and wear out faster than a (semi-modern) central unit, though you can again save energy by only cooling to a lower temp, the rooms you need to. Plus several window units are higher maintenance than one central unit, though the upside to them is if you aren't well versed in DIY HVAC, you may avoid labor costs by replacing your window units instead of calling in an HVAC company to replace central unit parts. These days just having an HVAC company make a house call, before parts+ costs, can cost about as much as a modest sized window unit.