Got any examples? Of the "before" and "after" variety?
Certainly!
Throughout all three DVD sets, instances of various exclamations and interjections were all streamlined to default to such phrases as "Scrap!" and "By the AllSpark!" This was done arbitrarily as though someone just did a quick "Find and replace" for certain words that had originally been used in the Metrodome subtitle scripts, with "Scrap" inserted in their stead, result in such awkward cases as "Scrap you!" and "Scrap it!" To say nothing of the fact that the AllSpark (the life-giving cube or other polyhedral relic, specifically) did not and does not exist in JG1.
In The Headmasters, every single instance of the words "Cassette", "Cassettron", and "Cassettebot" (the latter two of which had already been appropriately localized by Metrodome's subs as "Decepticon Cassette" and "Autobot Cassette", respectively) was changed to "Deployer", which is what the then-new Exodus novel referred to Soundwave's minions as before the RID 2015 toyline would instead apply that term to individuals like Soundwave who had smaller minions (e.g. - Drift, Fracture, Overload, and Crazybolt) instead of the minions themselves. In the case of The Headmasters, this meant that an anachronistic term was put into use for a series that long predated even the original use of the Deployer term from Beast Machines, and anyone watching the DVDs with no familiarity with the "Deployer" term was given no context for it whatsoever. For instance, the title of the series's fourth episode, which Metrodome had subbed as "Operation: Cassette", was now subbed as the more awkward "Operation: Autobot Deployers".
When Sixshot first introduces himself to Ultra Magnus in the first episode of The Headmasters, he refers to himself with the title of "Destron Dinobase Ninja Sanbō" (デストロンダイノベース忍者参謀), which Metrodome had previously subtitled as "Decepticon Dinobase Ninja Commander". The Shout subs instead changed this altogether to "Phase Six Decepticon officer", in deliberate reference to IDW1 Sixshot being a Phase Sixer, which is a concept that has zero presence in JG1 and did not exist until decades after The Headmasters. It also removed the point of the original Japanese title that presented Sixshot as the Decepticon counterpart of Ultra Magnus, in that both were the commanders of their respective cities, with Magnus being the City Commander of Autobot City (which included Metroplex) while Sixshot was the commander of Dinobase, which was the Japanese name of Trypticon's city mode. This was meant to further setup the rivalry the two would have over the course of the series, but the "Phase Six" reference ruined that setup by nixing it altogether in favor of a nod to something that has no business being in The Headmasters.
In the third episode of The Headmasters, we got a TFTM reference that completely inversed the context of the original Japanese dialogue that it replaced. In this episode, the Autobots were trying to get the Matrix back to full power so that it could help them to stabilize Vector Sigma, which had started running out of control ever since the Matrix had lost all its energy back in "The Return of Optimus Prime, Part 2". The Matrix and Vector Sigma shared a connection that made the power of the Matrix vital to Vector Sigma as well. Near the end of the episode, the Autobots had brought the Matrix to Vector Sigma's chamber, where the ghost of Alpha Trion instructed Hot Rod to lift it up high so that he (Trion) could use the last of his own energy to fully restore the Matrix (which had been only partially restored by that point, Trion was going to top off its power to bring Matrix back to 100% power). When Alpha Trion's ghost sacrificed the last of his essence to the Matrix, he spoke directly to the Matrix itself, beckoning it to please be restored with cosmic wisdom and power in this final act by Alpha Trion. In other words, the Matrix was the one in need during this scene, the one being saved by the others. For once, it wasn't the one doing the saving like it so often does in other cases. The Shout subtitles, however,
completely inverted that whole point! They replaced Alpha Trion's beckoning speech wholecloth with "May the Matrix of Leadership light out darkest hour!"
That is not what was happening! The Matrix didn't light anyone's darkest hour, Alpha Trion lit the
Matrix's darkest hour! Not the other way around!
Meanwhile, in the Masterforce subs, every instance talking about the different kinds of Chokon Power was changed to instead talk about Energon, with all three powers changed to "Earth Energon" for Chichokon, "Star Energon" for Tenchokon, and "Spark Energon" for Jinchokon, removing all of the original mysticism behind the three Chokon Powers since now they're just Energon. Because humans
totally have "Spark Energon" running through their flesh and blood bodies.