I honestly, wouldn't get your hopes for a return or continuation of previous series if I were you. Any return to previous series, especially Adventure (Season One) is unlikely; the anniversary would be at it's tail end, if at all, and when this airs, Savers/Data Squad will have aired "4 years ago," which aired after Frontier ended "4 years prior" to that. So that's 8 years since the first four series, let alone the first two. How is that a suitable marketing strategy to begin a new series for a new decade, who's target audience would barely remember or even know of those series? You can't rely solely on "Nostalgia" and an ardent older niche fanbase to get something that will actually last as a continuing franchise for more than a year or two.
Plus the stories are over, with all their triumphs and failures therein, the original producers and staff behind them have likely moved on since it has been a decade or so hence, and do you honestly want a continuation of "your favourite childhood show," with no reboot, or renewal, if not done by the original people? And really what more can be said, all the stories "ended." Going back now, after so long, would either undo the endings (which has more negative complications than you might think at first) or cause an unsuccessful
Postscript Season, and when relying on "nostalgia," such a sentiment would certainly head towards cries of "Ruined Forever" and such, and the series' ratings and sales would likely plummet.
Sometimes, like with Super Sentai and Kamen Rider, renewal is needed to seed the next generation. The general direction of Savers/Data Squad was this, reinvent the series for a new audience, while aging things up a tad and banking on the "grown up" original fanbase (who expect more action, content, and older-Shonenesque concepts than before) and their nostalgia (i.e. Agumon, emphasis on partners (Human and Digimon alike), and various cameos, for example) to help add to things and possibly reel in their younger relations while they're at it.
That and each incarnation has reflected on popular concepts (particularly technology) of that era for gimmicks and stylistic ideas. Early 2000 tech (such as mini-laptops, digital watches/calculators/early cellphones, etc.) just wouldn't fly today (and if using the distant finale of 02, which is honestly the only place where Adventure (01/02) can continue from, story wise, would be "future tech" of a "past future" which really wouldn't work with the whole concept of Digimon being based on the premise of "Monsters from your Computer/Cyberspace"). New trends need to be reflected to keep up-to-date, after all the "it could be real..." atmosphere was kind of part of the attraction of the series.
At any rate it's inadvisable to hold on to "wish-fullfillment" or "false high hopes," especially based on nostalgia and at the same argue what it "should be" and eventually get into the "which series is the true series" debate" when, as stated already, this is still unconfirmed, a rumour with only some minor credibility if you will. Can we wait until it is officially made certain this month or early January, that Digimon Around even exists before we get into debates, complaints or demands about how the show could "possibly" be run? I'm just happy it might have a chance of coming back at all, let alone if it will be a "true continuation."
And on the topic of favoured series, I happen to like them all pretty equally, with a slight bit of preference for Tamers and maybe Savers/Data Squad. And I actually liked the 02 Epilouge. True, it kind of came out of left field, but the possible futures seemed to fit the characters and it ended off on a high note with a "the story continues on" type of conclusion without feeling like a cliffhanger or requiring any more resolution. The MaloMyotismon battle, that could have used some reworking; it likely would have made more sense had they referenced dreams as a dominant theme, particularly Davis/Daisuke's dream, prior to that.
And before it gets brought up, the Savers/Data Squad Citramon (BomberNanimon) thing was sort of forced on them, they did not intentionally go into it to do that. According to Jeff Nimoy, he was told that the giant walking bomb had to be censored or the episode was cut; and so they made the best of a bad situation, kind of going for the "So Bad Its Good" angle and sort of lampshading the whole thing by making the situation as over the top as possible. Believe me, it could have been a lot worse and there are far more important things to complain about, some being things that were already in Savers, than a single Digimon alteration in essentially a "filler" episode.