It's normal. You're never guaranteed to get 4 different upgrades on a gold mod. You only get the assurance of seeing the non-upgraded speed already revealed, and the possibility that any (or all) of the upgrades could hit the speed stat. But it has been random, and still remains random, which stats will actually get upgraded.
If you're prone to donning a tinfoil hat, the rule of thumb is that the chance for the speed to upgrade is approximately zero percent by design, because that's how they get ya. :)