Bearing in mind that the iPad recycle is around every 18 months I would be surprised to see a replacement for the iPad Pro after just 11 months.
This is my favorite
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Technology moves fast and our memory is short. There’s not that much history to the iPad Pro line by itself to really definitively say it has even a rough release cadence of its own. iPad line in general has gotten busier with the entry level iPad, the Mini, now the Air sitting between entry level and Pro... but if you look at the entire history of iPad releases, a yearly cadence is far more common than not.
iPad: April 2010.
iPad 2: March 2011. (11 months)
iPad 3: March 2012. (12 months).
iPad 4, iPad Mini: October 2012. (6 months. Very much a spec bump if I recall correctly. Faster chip - a6x - and moved to lightning connector instead of 30pin. A lot of iPad 3 owners were not happy about the quick update... I bought an iPad 3 and don’t recall the iPad 4 release really bothering me.)
iPad Air, iPad Mini w. Retina: October 2013 (12 months)
iPad Air 2, iPad Mini 3: October 2014 (12 months)
iPad Pro 12.9”: October 2015 (iPad Mini 4) (12 months from previous “flagship” iPad release— the Pro line became the new flagship, I’d argue).
iPad Pro 9.7”: March 2016 (17 months from previous 9.7” iPad)
iPad 5: March 2017;
iPad Pro 2nd gen: June 2017 (15 - 20 months from first gen Pro)
iPad 6: March 2018;
iPad Pro 3rd gen: October 2018 (16 months from 2nd gen)
iPad Air 3, iPad Mini 5: March 2019
give or take a couple weeks on these— sometimes they were announce in late October and shipped early November, etc.
Now, you can see where the estimation fo the iPad Pro’s release cadence comes from... but in the larger context of iPad releases over time, it would also not be unusual for an annual update cycle.
Yes, there has been no other product with as regular a cycle as the iPhone; we shouldn’t necessarily expect a new iPad in a given tier every 12 months the same way we do an iPhone... but it’s also not unreasonably soon, either, especially for a modest update that serves to keep the product fresh between more major updates.
Also... the Air 3 seems like it sits in a weird spot right now, although I see how it sits between the “budget” model and the Pro model. I’m very curious to see what happens next with regards to a 10.2” model (iPad 7? Why would it be rumored to get a better 2-camera module over the Air line?)