Today I got a strange login procedure where myibidder requested to link to an ebay account and when ebay asked for permission to link with myibidder.

Up to now I always assumed that ebay did not need to know whether I do use an automatic bidder.

I wonder why such a drastic (?) change did not make it into any announcement.

What are the consequences of that change?

That's just a new way to access your account which should improve reliability of your snipes.

eBay knew you are using a sniper in the past too -- having hundreds or bids coming from the same IPs everyday on last seconds is a good sign showing these are snipers.

Please check this forum thread: https://www.myibidder.com/forums/viewtopic/7961/msg-your-ebay-account-is-not-linked-to-the-sniper/