Basically, Authorize.net is moving their services to a new provider. They already have the new service setup and it’s running in conjunction with the old service until June 2016. The existing links all still point to the old service. They setup new transaction urls to point to the new service and have started asking customers to start using it instead of the old servers.
Does affect my use of eAuthorize?
The short answer, no. The longer answer is not really.
Version 5.2 of the plugin, has the ability to specify the Authorize.net url in the settings for the plugin. eAuthorize 5.2 users can start using the new urls that authorize.net included in emails to you. You can begin using them right now if you like. It should be a seamless transition.
If you do nothing, eventually authorize.net will change their old transaction url to point to the new servers. Eventually, you will see transactions resolve to the new servers instead of the old ones. This change happens at authorize.net and not in the plugin.
If you are running version 5.1 of the plugin, you must wait for authorize.net to do the redirection and send the old url to the new transaction servers. Those older plugins don’t have any way of changing or controlling the url to which they point.
A 5.2 customer does have that control. They can choose to wait or they can proactively make the change themselves.