Indeed. Business don't care about flatly letting their staff get perks. They might be interested in providing perks to some staff, but that would have to be their rules and their choice. Failing that, effectively paying too much so an airline can give "free" perks on your dime is financially totally counter-productive and if businesses do end up giving more of their business to BA, the immediate result will simply be to want a bigger rebate on the corporate contract (they are typically sliding scales anyway so it will partly happen automatically anyway), so you'll end up losing much of what you have gained...