So this came to me while reading the "complaint", for lack of a better word, on the Transformation Name Announcement page for Digimon, specifically that the Digimon say/shout/"call out" the name of the form they are digivolving into. I remember that the formula was [Current form] (any special sub-set) digivolves to: [New Form]. What recently struck me is how similar this looks to computer code (in an object-oriented programming language, such as what the Digital World could be programmed in). Digivolution would be a method called on objects, i.e. the Digimon, and the new form is listed as a parameter of the method. Thus the "phrase" is necessary to digivolve, because they are actually reshaping their (digital) reality.
To expand, when they call their attacks, they are basically calling This.PepperBreath() or This.RiverOfPower(), this calling the method that creates a beam object.
Originally, the movies were about introducing new concepts to the Series. So, by that theory, Digimon Adventure (the first movie, which appeared before the series proper) introduced the idea of children caring for a monster, and having said monster protecting them from another, thus introduced digimon adventure. Our War Game introduced DNA evolution and children getting digimon from watching them, as well as acessing a digital world through a computer. Revenge of Diablomon introduced angel like, immenselly powerful enemies and NGE Imagery (Omegamon sans arms, anyone?). Runaway locomon introduced... train digimon? Naturally, this ends with Frontier, because there isn't any series in the following year, and doesn't aply to future seasons.
Actually, Island of Lost Digimon introduced Beast Digimon warring with Human Digimon, very similar to Digimon warring with actual Humans in Digimon Savers. And Activate Burst Mode had multiple Digimon and only one human (-like creature - Rythim), similar to Digimon Xros Wars.
From that point of view it does apply to all seasons (since akari and zenjirou cold have only been put in the show because of fandom complaints)... Then, hopefully xros wars will get a movie, because otherwise that would mean the end of the anime series.
All Digimon are essentially programs, presumably of the same filetype. OF COURSE their names all end in the same 3 letters. Just like .exe, .jpg, .png. etc.
So it really could be written as digi.mon. Examples: Agu.mon, Gabu.mon, Vee.mon?
Because of this, it actually makes sense for certain digimon to be named differently between original Japanese versions and dubbed. After all, you can rename files easily. It can also work with changes like Bomber Nanimon to Citrimon, since you can also modify files based on type too.
From a certain standpoint, the Ophanimon/Magnadramon confusion regarding which one of them is the true Mega form for Gatomon is intentional; they both are!: Ophanimon would be the goodSlide Digivolution, while Magnadramon is the bestial state of being, and Lilithmon the evil one.