Are you seriously asserting that the removal of a class from the AD&D 2nd edition --- a class that had existed since 1975 --- did not constitute a rules change?
You're being very disingenuous with your description, since the removal of the class was not as permanent as you imply - as I've explained but you simply ignore, because it's not convenient to your (autistic?) narrative.
The presence or absence of the Assassin sub-class in the
core rule book has no effect on
any campaign setting.
As for the notion of assassins being a sub-class available as an option, this was not true of AD&D 2nd edition; at most, there was an assassin "kit" included amongst 18 such kits for thieves in The Complete Thief's Handbook, i.e. an optional part of an optional accessory.
What makes this particularly disingenuous is that you're basically rewriting exactly what I wrote, but with a biased slant, and is lined with internal inconsistencies as is typical for someone trying to twist facts into something that fits their narrative, as opposed to reality. Re-posting the screenshot I posted, is also very disingenuous, the question posed by the turkaroach was very open to any interpretation, probably not by design, but by incompetence and limited language skills.
Assassins are available in AD&D 2nd edition, as you yourself concede, as a class kit - i.e. a sub-class of thieves. The 2nd edition was simply designed that way, that's why it's a new edition. Optional accessories are a completely legitimate part of the 2nd edition as anything, but this way they sell more books for TSR - you also very casually brush over the fact that the Forgotten Realms campaign setting is itself an
optional accessory.
To quote Jeff Grubb from Dragon Magazine #153 (January 1990): "Of course, there's more, I continued. A lot of little things changed with the appearance of the AD&D 2nd Edition game, such as the nature of spell lists and the official introduction of proficiencies and ability checks. The FORGOTTEN REALMS setting is TSR's official AD&D 2nd Edition world. In showing how we made the switch to the AD&D 2nd Edition game, we show all the other DMs how to make the transition, both for their own worlds and for the Realms."
A fantastic quote, and it doesn't actually support your bizarre claim at all - i.e. that the Avatar trilogy was written to explain rule-changes.
What Jeff mentions is changes to spell list, proficiencies made official, ability checks and so on - all rule changes from 1st edition to 2nd edition - and
none of them exemplified or explained in any way, shape or form in the Avatar trilogy.
He's talking about the new Gold Box campaign setting, not the Avatar trilogy.
Or to quote from the end of FRE3 Waterdeep: "Now the purpose of the Avatar storyline becomes clear: It provides a golden opportunity for DMs to change from the original AD&D® game to the AD&D 2nd Edition rules."
Yes, this is exactly what I've been saying - it's a golden opportunity to buy the new books. To dump 1st edition for the 2nd edition.
Is your particular autism preventing you from reading and comprehending text, because your quote supports my claim and undermines yours.
The purpose of the Avatar storyline is very clear indeed: it provides a great opportunity for people who had the 1st edition AD&D to change to 2nd edition. Nowhere does it mention that its purpose was to explain rule-changes.
FRE3: Waterdeep is an adventure module, it ties directly to the Avatar trilogy and it is 2nd edition AD&D. A golden opportunity to upgrade to 2nd edition, indeed.