It should be a legitimate concern. Is the bolt easier to stretch or the metal easier to crush? I'd venture to say it's borderline on which gives first. If there was a sleeve the bolts would stretch first 100% If you bolted them up and torqued, I bet you get a nice witness mark in the metal.
FWIW, I have the Hotchkis 108" WB weld-on connectors and they are nice pieces. Creates a nice line between the front and rear subframes to send stress through the chassis. They also designed it to create a large amount of weld area to increase stiffness.