I thought the STO was supposed to start quite soon, i don't understand why announce it now when there could be even delays before the platform it's ready to handle it.
This is also about the marketing of course, this news will be able to increase people's awareness about Dusk platform and make it become more attractive.
It's quite obvious that the STO can't start before the DUSK platform isn't live. Now Dusk has its tokensale so it makes sense to show potential investors that there are already projects which are interested in hosting their STO on the DUSK platform. So it totally makes sense to announce it now, even though it will only start in a few months.