Depends on how important it is to customers. Waterproofing was always just an excuse to seal the case and make repairs harder, and wasn't a feature that the market demanded. We always had waterproof phones for people who needed them. You can seal a battery compartment to IP68 with a bit of effort, and IP44 is essentially what you need to put it in your pocket anyway.
Would you pay extra for waterproofing? If so how much?
I think all phone lines should have a waterproof option that doesn't have a an easy to remove battery. That way consumers are given the choice at the time of purchase, and the people that want waterproofing are the only ones affected by the repairability tradeoff.
The Samsung S5 has an IP67 rating and the battery on that was easy to replace.
If you drop either phone they are probably just as likely to be compromised.
I could see a latch that you need the sim ejector to open. Something that still very secure, but possible for an user user to replace with out the need of a freaking heat gun. While still keeping the design.