I'm not sure what the logistics look like with 7 months notice, but I'm turned off by the implication that if DT doesn't show up it validates his position. Disregarding for a moment whether DT has any interest in this, there's a huge difference (financial and logistic) between flying to a venue for a one-off performance and dedicating an entire week on a cruise. While I wouldn't go so far as to say it was intentional on MP's part, I can't help but think that he gave them an offer that he knew they would decline.
Absolutely.
I mean, when it comes to whether to invite them, he's kind of in a bind. He risks negativity from the fanbase and from his former bandmates if he doesn't invite them, but he also kind of sets himself up for the same thing if he does invite them, because it is almost certain they don't come--not necessarily because of any negativity towards him, but mainly because of the logistics of the thing. All in all, I think he probably comes out better by inviting them. The problem is, he loses any potential saving grace and makes himself again look very low-class by making the follow-up comments he made.
I think he could come out of this whole deal very well if he invited them and just didn't comment much about it or chose his words more carefully. I disagree with your earlier comment about looking for reasons to hate Portnoy, he chooses time after time to walk that fine line between taking the high road and putting the blame on them.
He could refer to "Dream Theater" as a band of 5 members that doesn't include him right now, or rather refer to his 4 former bandmates in a clearer way that doesn't sound like he's ignoring the presence of MM in the band ("My 4 bandmates from the band", "The members I'm more familiar with", etc.).
He could
not address random comments on Facebook all the time talking implicitly about how he thinks the band is holding a grudge or something, or about what he thinks is the actual reason for them to refuse, or to keep harping on how much he's hurt from their refusal.
He could
not retweet, like and share various comments throughout the years about how so and so album of DT recorded without him is terrible, sounds too much like Images and Words, how they're not what they used to be without him, and many many more of these.
He could stop bringing up the term "reuniting at any point" as if we're still talking about an end goal that may and will eventually happen, but rather talk about it like it is: A likely permanent separation. There can be collaborations, there can be reunion *shows*, but he chooses to say it as if he's expecting them to actually reunite with him in the long term.
MP is a big boy and he's making it very hard to relate to him in this whole ordeal. He's absolutely responsible for the negative image he has publicly among some DT fans and I don't think you can blame it on them. He's always choosing to tread along this line of bitterness and passive aggressive comments about the band when the "breakup" was supposedly smooth and mutually agreed on, he's always putting out the dirty laundry, he's always encouraging campy behavior in the fanbase. He chose to have a solo career and that's fine, but this band really doesn't need periodic tackles and drama with ex-bandmates in my opinion, this is not Guns n' Roses or Queensryche; but he keeps steering the wheel in that direction IMO.