Most organizations allow silver, gold etc. supporting memberships, where companies more interested in the organization pay more to signal their support (and, presumably to a lesser extent, to get promoted more by the organization). Having something like that definitely makes sense. I don't see the point in tying it to how many MediaWiki users the company has, though. That only seems to have disadvantages: it discourages organizations with a large userbase but small support budget from supporting at all, and prevents organizations with a small internal MediaWiki userbase (to make up a random example, Wikia/Fandom is a huge MediaWiki user but their entire staff is less than 500) from supporting at a higher level.
