Yes, absolutely. So every ship from any cruise line that goes to Glacier Bay gets actual park rangers for that day. My only point is that Disney actually has a naturalist on the ship for the whole voyage, and does nature and history talks for the whole cruise. I think that's ultimately better, if the naturalist is good. One of ours (Doug) was good, but the guy that replaced him when we hit Juneau was not very good.
I really hope when they do the next round of Glacier Bay permit bids that Disney puts in a bid. It's really too bad people have to choose between Disney and Glacier Bay. I read somewhere that Disney had intended to bid in the last round, like 5-ish years ago, but pulled out at the last minute. Maybe they realized that if they got fewer Glacier Bay permits than they wanted for the season, they'd still have to send some of the cruises to Tracy Arm or another glacier location, so it was easier to just concentrate their efforts on one itinerary rather than having to develop several.
Edit: here's the article that talks about the current permittees and mentions Disney pulling their bid:
http://www.travelweekly.com/Cruise-Travel/Alaska-s-Glacier-Bay-awards-10-year-deals-to-cruise-lines