In theory, to win the business if prices are comparable (or within the Concur tolerances).
More practically, companies use status matching as a strategy to move travelers. If I were still a corporate travel manager during this AA/NDC mess, I would have made arrangements with UA and DL to do free/unlimited status matching for AA travelers as a means to get them off AA.
In a previous life (and close to 15 years ago) I was at one of the Big 4 accounting firms when they removed PMUA as a preferred carrier. Some of you on here may remember which firm. They indeed negotiated like-for-like status matches to the other US majors (AA, US, and DL with their newly merged program) as a means to get people off UA. As I recall, hub captives stayed put, as did some die hard loyalists who found back doors via codeshare bookings. In the end the UA/CO merger caused it to become a non-issue within another year anyway.