I think the purpose of supporting HD has kinda gotten lost here...
It has not gotten lost. However, When there are so many other options to choose from, buying HD only tells them 2 things, either or.
A. You liked it, and want to see more of it,
and
B. You will buy anything Castlevania related they shit out, regardless of quality.
By buying everything on the list EXCEPT HD, it sens out a message thay you like what they have been doing with say, The Adventure Rebirth and the ports of SoTN, but that you dont like what they did with HD.
They look at the sales, and they will see the others sold better than the one.
Unfortunately with Castlevania, there is not as much merchandise to buy as with say, Mega Man, who has been all about merchandise recently, despite a lack of games.
So you have to do what you can. send messages, and not just to Konami US, because that have little power over these things. But Konami Japan. Like 100,000 Strong did. get ahold of someone who can write japanese and make a well put together message and have everyone email it directly to them. And then include a personal message. Im certain the DO have translators who can read those emails.
OH --and about the Anniversary... It's the spark that got the Operation started. Now that the introduction video is out of the way, next will be an actual Tribute. Watch for it that weekend --the 23rd or 24th perhaps...
in that case, you can switch focus now to the preservation of 2D gameplay, and the completion of the classic timeline.