M2P in network mode is "leaking" pages into other sites on the WPMS network.
In this particular instance, post ID 474 happens to be a Page in one particular site, and once M2P was deployed, that page disappeared. It also happens that post ID 474 in rootsite (where the M2P pages are) is an email template (in this case, the recurring payment failure email).
On the site where the page disappeared, in "All Pages" the entry where the missing page should have been, the type is listed as "Membership2 Email Templates". See the attached screenshot for what I mean. Note that the title has changed as well as the post type.
This is only one example I know of. It seems likely that M2P is interfering with pages on other sites right across the network, so this is a semi-urgent bug to fix.