In short, Iberia splits allocation of Avios reward seats into two fare buckets – ‘Blue Class’ and ‘Economy Class’. Blue Class is an allocation of discounted economy redemption seats, which equivalent to a ‘saver’ or restrictive fare class on other airlines.
The only real difference between a Blue and regular Economy class fare is the change and cancellation terms/fees with no difference on seat selection, checked bags or carry on (both being the same).
At the time of writing Iberia Blue Class and Business awards have 25 Euro change or cancellation fee. So while the incentive to cancel isn’t that expensive, there is usually a premium to booking a more ‘flexible’ ticket.
Iberia and British Airways.
Being part of the same group, British Airways allows you to redeem Iberia flights on their website. In fact, if you do a search, the availability shown on BA.com is the Blue Class allocation. What iberia.com shows as ‘Economy Class’ reward availability on Iberia flights is not available via ba.com. You can only book them via iberia.com for a 50% premium to the usual Avios price.