I'm not sure how significant knowing the value of the next token is to the bidding or use of Conan; each token has significant value in the game. I can't help but wonder how more intense the bidding process will if no player knows what any player has, (as far as the tokens are concerned).
I don't think it would intensify the bidding process at all. It simply changes a strategic element to an entirely luck based one. If I know another player has acquired several monster trophies, for example, and the new adventure reveals several more monster trophies, you can bet there's going to be some fierce bidding. The player with the trophies will bid high to get more, other players will bid high to prevent this from happening, while building up their own numbers.
Another example would be if there are a bunch of trophies worth two gold or spell icons on them and I need gold to refresh cards or spells tokens to play Kingdom cards, then I would bid high.
However, if the adventure tokens are hidden, then it's a crap shoot. I'd be pissed if I bid high, only to find a bunch of value 1 trophies or trophies that aren't worth very much gold or spell tokens. If it all comes down to luck,then there would be no reason to simply use your highest card and the "3" bid token, saving your "6" to try to crown Conan in the 3rd age. Things like remaining "Court" action dice in the pool wouldn't be as significant, at least where bidding was concerned.
But don't let me stop you from trying it out and letting us know how it goes.