I don't think so. I think it would make it more interesting. Teams like Essendon, Hawthorn, Collingwood and Melbourne would be doing absolutely everything they could to win over these next three weeks to get one of those wildcard spots. Instead, the Dees are essentially dead in the water now and Collingwood + Hawthorn will be in the same position unless they upset their top 8 opponents this weekend. Plus, you get 1-2 more marquee games on the calendar each season and that means more coverage, more ratings, more sponsors etc. Imagine Collingwood v Carlton in a wildcard playoff game - that's a realistic possibility with the way the ladder looks right now.Would it devalue these last few rounds though?
The goal should be to have as many highly competitive games as possible before the finals start. Right now we have around half the league with no real incentive to win in these last 3 weeks and very real incentive to lose in order to improve their draft position. No matter how you look at it, we're probably going to have to expand the post-season competition soon anyway given Tasmania's imminent entry into the league.