Should and would are two totally different things. ;D That's also assuming the difference in length is minimal enough not to disrupt ramp engagement. What happens if it's to long and results in little to no lug contact? The bolt head will be too far forward to be supported by the ramps and/or could contact the breech face before the bolt handle is forward enough to let you close the bolt. The later would be obvious as you wouldn't be able to close the bolt, but you'd have no way of checking the lug to ramp contact without pulling the barrel.

I've seen more than a few bolt bodies come into Fred's shop from Savage that were way out of spec on the length, so it's definitely a possibility. If they're blatantly long or short you'll know immediately as the bolt won't close, but a small difference in length could easily affect ramp engagement and/or change bolt head to breech clearance (which falls into the realm of headspace)

For example, lets assume the face of your bolt head is 0.010" short of what is considered spec (0.130" deep) and we install a new bolt body that's 0.010" longer than our old one on the front end. That's probably not enough of a difference to cause an functional issue, but it will affect the head space as we're now positioning the bolt head 0.010" closer to the breech. As a result the gap between the bolt head and breech will be 0.010" smaller meaning our brass will be to long to chamber as the shoulder will bottom out in the chamber.

Why would this change the headspace? Because the bolt head variance is on the front side, not the rear which contacts the ramps. The spacing from the through pin and the rear face of the lugs on the bolt head is the same as what it was before, but the through bolt hole on the body is now 0.010" further forward compared to the old one so it will push the whole bolt head forward by that amount. Depending on how precisely the chamber depth was cut on your barrel and how tight or loose the headspace was set before, that small difference in length could cause a problem.

All in all it's a potential safety concern, and given how easy it is to check and/or correct it just makes sense to take the five minutes to do it...if not for safety then for peace of mind.