No, you're correct MrFuji, shove is 100% guaranteed to succeed without a check or save, if you are hidden from your target when you shove them (and providing that they are a target that can be shoved, and you re not attempting to shove them somewhere impossible - marked by a red line). This has been the mechanic across all patches and has not changed. Any report to the contrary would require some data, as it's far more likely that the reporter simply missed one of those other details.
For clarity, to RumRunner, no-one has, at any point, ever, suggested that heavy armour stealth should automatically fail. Please refrain from painting the people you disagree with in false or disingenuous lights.
Accounting for sound and using player's stealth scores to determine success and failure consistently is not difficult; a contemporary D&D video game does this with aplomb, in fact. It uses passive stealth and passive perception to generate a detection radius and an awareness radius - the lower your stealth score, the larger your 'ping', and thus the more easily you are discovered. The better the perception of a creature, the wider their detection radius (which you cannot see) is and the sooner they'll begin to take notice of targets sneaking around. Having disadvantage on stealth lowers your passive stealth by 5, which the game accounts for and uses correctly in this calculation. The game has a short leniency display that shows you when you're close to getting caught, and stepping into open line of sight in bright light results in automatic detection regardless of your stealth - no 'vision cones' are necessary for the game to convey this.
(Incidentally; this is an illustration of adapting an element of a PnP game's ruleset to a video game format and making changes to the way things work in that adaptation while still creating the spirit of the ruleset and respecting it. Again - not actually that hard to do, if you care about doing that.)
BG3's stealth system actively encourages you to circumvent the actual stealth mechanics - the tutorial literally shows you "avoid the big red vision cones and you'll never need to make a stealth check ever, no matter how bad your stealth is!" This, to the point that you can tromp about in a one-man-band rig, playing it with wild enthusiasm less than three feet from an enemy and know there is zero risk of them detecting you. They also make the parts that do engage with D&D's stealth rules so unfriendly in what can only be assumed to be a further effort to get you to ignore those rules and play their sight-cone mini game instead; by this I mean, when you do cross a sight cone, you don't just make one stealth check - you are spammed with them continuously every other second until you fail, even in turn based mode. They put stealth rules in, and then antagonistically brow-beat you into not engaging with them, so they can force you to pay attention to their Divinity stealth system instead. No-one should be defending this.
