Accessories maker Logitech appears to have accidentally revealed the existence of two as-yet unannounced new iPad Pro models. Earlier this week the product listing page for Logitech’s Crayon stylus was updated to include compatibility with two new tablets: the “iPad Pro 11-inch (4th gen)” and the “iPad Pro 12.9-inch (6th gen).” Both were labelled as “Coming Soon” in the listing. It’s widely expected that Apple will indeed launch two new iPad Pro models in the near future–most likely at an event in October. But they haven’t yet been announced. The most recent Pros are the 3rd- and 5th-gen versi…