I think I'm understanding your question. I believe when they cancelled Lightning Bolt (32 shared with TV) & SuperMax (25 dedicated) the new 10 & 20 plans were dedicated speeds. They later bumped it to 25.
I don't remember hearing that Lightning 50 was shared. Good to know! I remember mentioning to people grandfathered on Bolt that the dedicated 20 was similarly priced but probably better suited as it wasn't shared. Some switched right away, but I've seen people online saying they'd keep Bolt as long as possible. Sometimes the fastest overall speed isn't the best.
Authorized Service Provider (Contractor) for MTS Allstream. Any views expressed are my own.