As far as I know yes, especially as this engine is from Opel, but I would not get too much worried - 1.9JTS engine produces low torgue (especially at low rpm) vs. gearbox max specs, so gearbox is not so stressed comparing to e.g. 1.9JTDM or 1.75TBI. I used to have JTDM 2nd hand (bought it 2nd hand with 50kkm mileage), gearbox bearings were roaring from time I bought it (but that never increased over years). I only changed oil (was usd/dirty with tiny metalic fractions) and 2 differential bearings (that was easy enough to do but did not helped on roaring), then did 50kkm with no change to roaring (maybe fresh oil helped?), then I decided to do ECU program upgrade (190KM/380Nm) and happily used the car for further 35kkm, then decided to do gearbox repair (I knew that I will have problm selling car with roaring). Repair itself wasn't too expensive (in dealer service it is) - the guy from polish alfa romeo forum did the repair for me, cost of 6 Timken bearings was like EUR140, 3L of Tutela Matryx (we put 2.8L on dry gearbox, so extra 0.5L as recommended by M32 gurus) EUR35, and labour EUR 125 - that was cheap, and guy had a way of repairing gearbox without removing it from car. After repair I did further 10kkm, but then sold the car (needed SW + I wanted more fresher car and petrol). I know that dealers services in Poland charge like EUR 700-800, and sometimes they decide only change 1-2 damaged bearings (if you come across need of repair ever, alway change all 6, and use Timken only - that is recommendation of all polish M32 gurus I came across on forum)
I have M32 gearboox in currently owned 159 1.75TBI, and did ECU mod to 240BHP/370Nm, as far all good, but the car has only 55kkm mileage, and ECU mod was done only 3kkm ago. Anyway I do not get at all stressed by fact of having M32.
I changed oil (TBI M32 has 0.3L less manufacturer spec), added extra 0.25L, and added around 0.2L of AR9100.
If your bearings do not roar yet, I suggest you change the oil (do say 10-20km just before oil change, so you well warm the oil, and so more of old/used oil will go out of your gearbox), put extra 0.25L, and add someting like 0.25L of Archoil AR9100. If you only change oil, gearbox can't be treated as dry, so around 2.1L (vs 2.3 in user manual) fits in to be as much as manufacturer recommendation, then you add 0.25L extra and then 0.25L of Archoil.
There is hope that you will never experience problem of M32. Good example is my friends father 159 1.9JTDM from 2005 with 200kkm mileage - it is still quiet, no roaring at all - he didn't even changed gearbox oil ever, but just as old man he drives the car more carefully, so maybe that is change factor (no stresses to gearbox).
With 1.9JTS, I would rather get more worried about timing chain (but that can also be sorted out cheap using GM parts, as far as I know most fit - except cog/chaing wheels (not sure what is right english term), but these usually do not need to be changed) - keep engine oil rather close to max level, as well you can use AR9100 (around 0.2L for engine).