Not sure about drive shaft, but final drive oil change is done on first run in service - criminal!!
my 2007 GS I subsequently find was meant to get the later mk 2 bevel with a breather and shorter gear ratio - but UK mkt got stitched up and we all got old stock of the likes to fail design... these were originally fill and forget for life... but they soon changed tack
it self destructed from a OK to gone in two weeks at the start of this year after 4 fluid changes in its 38k mile life - I swapped for a secondhand mk 3 bevel with the breather and the bearing in oil from 2011 20k mile bike - (noting both ends of my original shaft were well lubed, had no slop in the UJs and it looked like it was brand new), but the later bevel whilst turning it felt very smooth and tight, like it had almost no wear, was noisy from the get go - at 60mph it had a whine by 70 it was loud and when you wobble the wheel with a DTI its outside spec - they had it back
the one win was the bike never gave the impression the shorter gearing was an issue - it just felt right from the get go - indeed I'd done 100 miles before I even remembered to see if the short gearing would ruin the bike ! - after 3 k miles it just a far better bike running the slightly shorter ratio - just like it was always meant to get before BM stitched up UK bikers !!!
I swapped it for a 2021 3000 mile like new R Ninety scambler bevel that gets the nappy bracket you need for the GS' and the very same ratio - this had zero slop with a DTI - but the fluid that came out was a nasty grey with the drain bung full of filings - and low and behold the same crappy whine but much fainter..
I had to fit a rear disc the other day as it was 0.5mm under min thickness - so drained the fluid on the scambler bevel 1.5 k miles after filling with the correct spec fluid - so a total life of 4.5 k miles and again it was a disgusting mess with filings all over the drain bung and a grey tinge to the fluid
My original bevel never had a whine in its life !!! So my view is they are definitely living up to their new reputation.....