Seems both Buena Vista Home Video and Nickelodeon supported some of the same properties in the early 1990s.
Buena Vista got the video rights to Bullwinkle, The Jim Henson Company's library, and Alvin and the Chipmunks, in that order, and then Nickelodeon started airing all three, also in that order.
Of course The Disney Channel did air some Henson Company properties at the time, and The Chipmunks Adventure did air on The Disney Channel (I think the channel also aired A Chipmunks Christmas at the time as well). And further on the Nickelodeon side of things, it seems like they might have been taking baby steps with some of those properties - the channel aired Muppet Babies first, then various specials (giving them a weekly slot that seemed to have been meant to be temporary before reducing airings to special occasions, mainly as part of Special Delivery, and then finally giving the specials a more permanent weekly spot) and THEN rerunning The Muppet Show. With Alvin, the channel aired The Alvin Show first and then added the more popular Alvin and the Chipmunks series (and recently started a brand-new Alviiiiin and the Chipmunks show), though I don't think any Chipmunks specials aired on Nick (besides the few that were in the Alvin and the Chipmunks syndication package). And I think segments from The Alvin Show were shown as part of Weinerville before Nickelodeon started rerunning The Alvin Show on its own, but I can't fully remember.
Could Nick have been making broadcast decisions based on what Buena Vista had the rights to? Though Nickelodeon did start airing Muppet stuff a little before Buena Vista officially launched the Jim Henson Video label.
Also, and I think I might have pointed this out somewhere on the forum before, it seems Buena Vista treated Bullwinkle differently from other properties. The videos came with a mini-catalog advertising just the Bullwinkle videos and no other Buena Vista/Disney video releases, Disney's mini-catalogs that advertised its video releases didn't include the Bullwinkle tapes, and the only advertisements on those tapes was a promo for other Bullwinkle videos at the very end. The only thing on those tapes to suggest they were released by a company associated with Disney was the fact that Buena Vista had a castle in its logo (which did confuse me as a child). But then the Jim Henson Video and Chipmunks video releases had mini-catalogs that were the same as what was sold with Walt Disney Home Video releases, including those and (I think) other Buena Vista videos along with Walt Disney Home Video releases (though Jim Henson Video typically got its own section at the end of the catalog, put upside-down to appear like it could be the front). Though I think there was a Chipmunks video release that contained a mini catalog for just Chipmunks releases.
The Jim Henson Video releases usually just advertised other Jim Henson Video releases, but there were some that advertised other releases from Walt Disney Home Video or Buena Vista Home Video, and I think the Chipmunks releases advertised other properties from the labels (I actually haven't watched many Chipmunks VHS tapes and can't remember what ads were on the ones I have watched, though I did watch a YouTube video of previews on the first Chipmunks Sing-Along tape and saw that all the promos were for Jim Henson Video releases), and these were sometimes advertised on videos from Walt Disney Home Video or other labels.
And I don't think non-Bullwinkle videos from Disney or Buena Vista Home Video had opening promos for the Bullwinkle videos, either, but I can't be fully sure (maybe there's a Disney video release I never watched that has such a promo).