As reported by Bleeding Cool (link: https://www.bleedingcool.com/2017/03...ou-ask-nicely/), some fans are able to get digital codes of the physical comics they have purchased.
Right now, it looks as though you might be able to get them to send you digital codes of the comics you've bought by jumping through a bunch of hoops if you're lucky enough. So I encourage everyone who liked the old Bonus Digital Comics system to get in touch with Marvel, a huge response may push them to return to the old program so that you don't have to resort to contacting and sending copies of your receipts etc.