This seems to be a media ploy devised by Villa or Benteke's agent to generate more interest in him, or push Liverpool towards finalizing a fee. The £32 million buyout clause is an absurd fee for a player like him, and what he would represent to United. Now I know it's unlikely that Woodward will pay it, and it's not my money per se either, but that type of fee sets a very dangerous precedent for future negotiations. £32 million is not a fee you should be paying for an above average striker that might never be an automatic starter in a team that will employ a 1 striker system in the near future, considering how Chelsea bought one of the Top 4 or 5 strikers in Europe for a similar kind of fee just last season.
If you need a backup that can serve as a plan B and tide the club over 1 or 2 seasons until we find a more longer term successor to Rooney, or give Wilson more room to grow slowly, why not sign someone like Fernando Llorente instead ? 30 years old so it's not like he's ancient by any means, taller than Benteke for those who prefer aerial ability, but with better Spanish technical skill, has over 50 European appearances for Athletic Club and Juventus, and will cost somewhere in the region of £10-12 million.
Signing Benteke might even inhibit us from signing a better striker (like Kane or maybe even Lewandowski, hypothetically of course) next summer, because then we'll have Rooney, £32 million man Benteke, the new guy, and Wilson all vying for one spot in the starting XI with Van Gaal's implementation of the 1-4-3-3. Hope this whole link is balls to be honest, rather him at Liverpool than United. They can pay his fee and wages now that the Sterling money is flowing in in exchange for above average striker performances.