> Pretending marriage equality was always on deck when Leno et al. were working on domestic partnership is the spin here
I'm not sure what you mean by “on deck”. If you mean tactically attainable, yes, there was a wide view even among advocates and allies that it was not. DP was a tactical advance, on that there was broad consensus (though, ironically, the anti-embourgeoisement radicals you point to support this weren't part of it, as they generally viewed marriage as an archaic social institution not to be sought or imitated, but to be eliminated.)
But your claim wasn't about what was viewed as politically pragmatic, but about DP status being seen by advocates and allies generally as “just and sufficient”, rather than unjust and insufficient because it was separate, but at least better than the status quo ante because it was—to the extent possible for the state alone—formally equal.
> and Obama was strategically lying when he too endorsed civil unions but rejected marriage equality
Disagreeing with a movements aspirations isn't a lie. Now, whether Obama was a secret supporter tactically lying to placate opponents, a moderate opponent of the goals of the movement telling the truth, or a stronger opponent telling tscticsl lies to get support of the movement while not alienating it's opponents is...well, completely irrelevant to whether the movement itself saw civil unions as “jist and sufficient” rather than merely a lesser injustice than the status quo ante.
> Either the advocates of the previous decade's reform were not telling the truth [...] or they meant what they said at the time.
You are conflating LGBTQ advocates with the politicians who were (or, in Obama's case, were not) involved in reforms. Those may be overlapping groups, but they aren't the same groups.
Now, if all you meant to say was that you identified with the narrow, political establishment group that endorsed civil unions as the end goal rather than the mainstream of LGBTQ advocates and allies at the time who openly called for marriage equality as the goal but accepted formally equal unions as a tactical advance, that's defensible. But it's not at all defensible to claim that the movement saw civil unions as “just and sufficient”, that was overtly never the case, whatever a handful of politicians trying to balance between the movement and conflicting groups might have said (and, who knows, might have even believed it when they said it.)