Warner Bros. isn't even considering doing anything with Crusade at this point, I'd bet the mortgage check on that.
Let's be realistic about this:
Warner Bros. hasn't even committed to doing B5 S2 yet - they (mean old corporate bastards that they are) would actually like to see if S1 makes a profit before they invest at least several hundred thousand dollars in preparing S2 for release.
And B5 is a show that ran for five full years, the last on a national cable network, and has acheived at least moderate "cult-hit" status.
Crusade was killed before it ever aired, has only 13 episodes available for release, and was heartily disliked by even a lot of hardcore B5 fans. Warner Bros. probably has an estimate of the percentage of B5 fans who would be likely to buy Crusade on DVD as well. Once they've released a couple of B5 seasons and know how many copies they're selling, they can apply that percentage to Crusade and figure out if the show is worth releasing on DVD as well. If the numbers add up, they'll almost certainly release if. If the numbers don't add up, you can be sure that they won't.
In any case, they aren't even going to consider the idea until at least two or three seasons of B5 have been released, because they don't have any reason to. More than likely they won't consider it until after they've released all five B5 seasons, especially given that Crusade is set after S5.
You have to understand that Warner Home Video does not see this stuff through a fan's eyes. They're businessmen, and their job is to make money for their shareholders. As much as we may enjoy speculating/fantasizing about "what comes next", they're wrapping up B5 S1 and putting out in the market. They'll think about what to do next in the B5 universe when they've seen some numbers on that. This reminds me a bit of the fellow who posted a message on the Sci-Fi board asking if anyone knew what extras were going to be on the B5 season two set.
Answer: Nobody knows, including Warner Home Video, because they aren't ready to go there yet. Same with Crusade.