Indeed it is correct, as Moodle bring to the table loads of features for a well built LMS and you can expect server requirements slightly more than usual CMS, but I have as well mentioned "Active Participants", means 20 people taking course on site at any given time and as well clicking a link on a same instance (which is unusual unless there is quiz going on), whilst you can have 10,000 registered users without any issues.
it wont be an issue for sharing the Moodle with hosted site, just keep eye on the memory usage and if it feels like getting in 50%+ band all the time, then you can move your site to a VPS any time, for 1000 participants (assuming not all active same time) you'll be safe even with even a pro class shared hosting costing in range of $10-$30 depending upon service provider.
I mentioned this at early stage as I dont want you to get in hassle as when participants started building up, as when planning for a system ideally it should be future safe for at least 6 months ahead. btw, what configuration you are on your current site? is it on a shared host? just asking if I feel like that needs a change at early stage then I'll tell you before you open the site to public and knowing your configuration, Rick will be able to shed more light on that as he is managing a VPS with open enrollment and he will be able to tell how many users his server is serving at any given time.
Even considering a worst case scenario, you still consider it safe as Moodle transfers over to new home in just 5 minutes.
