When it changed: Third Edition
In the beginning, Orcs were either Chaotic or Neutral. (Men and Magic, page 9, 1974). (In contrast, Goblins were only Chaotic, Men could be Lawful, Neutral, or Chaotic). This was before the two-axis model, which was first seen in Strategic Review #6 (page 4, Feb 1976), and that placed Orcs in Chaotic Evil on the grid. The Holmes 1977 Basic D&D had them on the grid there as well.
They were listed as Lawful Evil in AD&D 1e, and remained that way for AD&D 2e.
In B/X and BECMI (Molday/Mentzer/Et al). which were printed after AD&D 1e was published, orcs are listed as Chaotic (in the red Basic box, DM Guide, page 35).
3.0 and 3.5
Alignment system: This was a two-axis system; good-neutral-evil and lawful-neutral-chaotic, resulting in nine possible alignments.
Orcs: The racial entry for alignment reads "Often chaotic evil" (3.5) or "Usually chaotic evil" (3.0)
Alignment system: A one-axis, five-alignment system, consisting of lawful good - good - neutral - evil - chaotic evil. Lawful evil was not a possibility.
Orcs: All seven different orcs listed as chaotic evil
Alignment system: back to 3rd's two-axis gird
Orcs: All four different orcs listed as chaotic evil
Designer notes: Unknown
I was unable to find any designer intent articles on why this mechanical change was made. The fluff, however, remained mostly consistent. In the core rules for 3.5, 4, and 5, Orcs are portrayed as generally bloodthirsty and savage. They are also smart enough to follow or team up with more powerful creatures, such as orc chieftains or ogres, if it is to their advantage to do so.
3.5 Monster Manual, page 204
Orcs believe that to survive, they must conquer as much territory as possible, which puts them at odds with all intelligent creatures that live near them. They are constantly warring with or preparing to war with other humanoids, including other orc tribes. They can ally with other humanoids for a time but quickly rebel if not commanded by orcs.
4e Monster Manual, page 203
Orcs often fight alongside ogres, and they can be coerced or bullied into serving any dark overlord or wicked monster powerful enough to command their obedience.
5e Monster Manual, page 245
Strength and power are the greatest of orcish virtues, and orcs embrace all manner of mighty creatures in their tribes. Rejecting notions of racial purity, they proudly welcome ogres, trolls, half-orcs, and orogs into their ranks. As well, orcs respect and fear the size and power of evil giants, and often serve them as guards and soldiers.
Your quotation from the June 2020 article seems to indicate that the publisher, Wizards of the Coast, may be taking Orcs (and Drow) in new directions. This is relative to 5e's current description of orcs as chaotic evil, not relative to 2e's orcs as lawful evil.
A note on Strategic Review: how does that relate to 'official rules' of the game?
- Strategic Review is where a variety of new material was introduced, but this was before the internet and a lot of people didn't get exposed to it. For example, the Mind Flayer first appeared in Strategic Review, as did the Ranger PC class. Some people didn't see those two now-standard game icons until AD&D books came out.
- Strategic Review had seen seven issues when it was replaced with Dragon Magazine. Dragon was generally "you can use this" rather than "this is official" per Tim Kask, Dragon's original editor.