And in the sentence above that, they're "saving" 15 million in Microsoft licenses. So either they've paid 24 million to Microsoft this year, in which case their next year's expenses are dropping by over 60%, or it's the same pot of money, in which case their yearly bill dropped by 40%.

I get that 9 million sounds like a lot, but it's much, much lower than what they would've paid to Microsoft anyways. And those 9 million are advertised as a "one-off investment", while their contract with Microsoft was perpetual.