Not really sure what this would mean for Manchester United. My guess would be that this is a personal property of the Glazier family and not of Manchester United Football Club. The fact that the Glazers are selling it could mean many things
1.The Glazers are selling it to pay of some of their debts. They can probably conduct business from Old Trafford or maybe they play to buy a cheaper building.
OR
2 The Glazers are selling it because they are getting ready to leave England and there is a takeover of United in the pipeline buy either the Red Knights group or the Qatari Royal Family
OR
3. This building dies belong to the club and they plan to use the money to invest in the team
1.The Glazers are selling it to pay of some of their debts. They can probably conduct business from Old Trafford or maybe they play to buy a cheaper building.
OR
2 The Glazers are selling it because they are getting ready to leave England and there is a takeover of United in the pipeline buy either the Red Knights group or the Qatari Royal Family
OR
3. This building dies belong to the club and they plan to use the money to invest in the team