wrinkled (pleated) leaves usually signify a moisture deficit. this could be a humidity issue or a watering issue. if you are watering plenty, it could be a humidity issue or your orchid may be short on roots due to rot. it's a bit unclear whether the bark in your picture is wet or dry – usually if the plant has "accordion leaves" and is in a bark medium, it means the medium is drying up too fast. but if the bark is constantly wet, it could also mean the medium is breaking down. in any case, it's nothing major and is just an indication of low moisture levels. these leaves may never straighten out, but the newer ones won't crinkle.
ps: your orchid is in the Oncidium alliance.