I think it'd require Toei realizing that with shows like TMM, they have a limited mass-market window in the US, and that after that point they are catering to the niche via niche localizers that aren't going to layout that much for it upfront. The most they could push for by this point is that maybe if they cut it as part of a bundle deal to Funimation (TMM + a few other series,) you might get Funi pushing it to a wide audience, especially Del-Rey picked up the manga license with a fresh translation (as TPOP lost all their Kodansha titles.) Even the worst case in that scenario would be a regular strip on Funi's linear and plenty of online and on-demand exposure.
More realistically, kicking it to the Neo-ADV as part of a package would probably be better for both parties. It'd give Toei a partner that'd probably put the titles as a top-priority, ensuring they'd be treated very well, and it'd give Neo-ADV something they could push hard and use as a baseline back to prominence.
Of course, Toei's so huge that they probably don't care that they are leaving money on the table by not capitalizing on their legacy library via any means available. However, with the collapse in the nuraber of new series per season, they could cash in fast by being a bit more lenient with prices on their back-catalog. Anime nosed in early, before the overall credit crunch, but it seems to rebounding ahead of the economy as well. If Toei could got a lot of their backcatalog in the production pipeline in next couple years, they'd be positioning themselves to seize on that rebound, especially if digital download/streaming rights were included without a lot of hassle.
It might even coincide with another anime on regular TV renaissance as people who grew up in the mid-90's-to-mid-00's anime boom will getting old enough to get jobs at networks. There are a lot of future Jason DeMarcos and Sean Akins who got communications degrees because they'd like to run places like CN and Teletoon in the future. If nothing, even titles like TMM did end up on a digital-only linear or on on-demand, more and more people are going to end up with those services as analog services are discontinued. Shoot, even Hulu is ad-money and promotion for DVD sales.