I still say if manufacturer didnt want you to DRAIN the oil and wanted you to vaccuum it out thru the dipstick, they would not have installed a DRAIN PLUG! just sayin
I just did an oil change on one for a customer. I would for sure drain especially for the first time. the pickup screen behind the plug was 90% plugged with pieces of rtv from assembly and pieces of block casting. if this just got sucked out it would have lost oil pressure very soon. I agree sucking oil out works in some cases but with this type of filter system it should be drained from the plug.