Why would a company pay for "commercial support" of OpenJDK from IBM? I have used Java for 15 years and I don't know what "support" for a JDK would mean.
If you have paid support, a small team of engineers will dedicate their time to fix the bug for you and provide you with a patch, so you can move on. The patch can sometimes be specific for your platform and situation.
This is particularly true if you are stuck with older JDK version and cannot move forward for various reasons.