The Tl;Dr here is that the cost to them of operating the free tier is lower than what they estimate their Customer Acquisition Cost would be without a free tier, so the free tier generates better leads/conversions to their paid products at a lower cost than traditional sales and marketing.
As long as these economics continue to hold they'd be stupid to discontinue the free tier.
As long as these economics continue to hold they'd be stupid to discontinue the free tier.