If you look at the DVLA site, you are entitled to drive any motorcycle and a bus.
The categories has been reclassified and changed significantly since you passed your driving test . For example, you could ride any motorbike up to 250 cc on a provisional licence and there was just the one category for that. Now there are at least 3.
When you passed your test you could drive any vehicle up to 7 tonne. That has changed, with more categories and classes. A newly qualified driver can only drive up to 3.5 tonnes now, and has to take an extra test to drive up to 7.
It doesn't mean your entitlement has changed - you can still drive the same vehicles as you could when you passed your test.