Advanced Train Ticket Avant Westcoast amended timetable question

Quick question that I wondered if someone could answer for me please?

I signed up for Advanced Tickets with Avanti West Coast, and got an email on 23 September.

I chose the journey dates and times on that date. They are Advance Tickets that I purchased.

I’ve just checked now to see if there will be any disruption on the 21, 24 November. Our outward journey, the time train we picked is still the same (so no change).

However the return journey the timetable has been amended and the 17:30 train that we chose originally when we purchased the tickets, is no longer shown, and instead is a 17:09 service. The 17:09 service avoids Birmingham on its journey to Glasgow Central. The original 17:30 train that we originally chose also avoided Birmingham to. We purposely chose a journey that avoids Birmingham as it makes our journey around 50-60 minutes less.

I was wondering if we would be able to travel back on the 17:09 train, without incurring an extra fee, as the way I see it is, we were able to buy the ticket originally through the email Avanti sent us to notify us that Advanced Tickets were available for the dates of our travel, and therefore the fault/change of train time is with Avanti.