I'm pretty sure there'll be a package for self-employed people this week. But FWIW I think it really is a lot trickier than for employees. There's a simple test for employees: they have a job but no work. A simple mechanism: the employer and PAYE. And at least a chance of audit.
The self-employed are different. Hard for HMG to know who like you has no work at all as a result of the virus; who less but still a decent income; some no change at all (eg coders already working from home); and some a lot more (eg an HGV driver I know with his own unit is coining it). Helicopter money (giving everyone a grant of say £24k a year) would be expensive and not go down well with employees - the more so when around half of all self-employed people declare profits of less than £5,000 a year. Could use on average profits for 3 years - but a lot of self-employments last less than a year. Then there's no simple mechanism to get the money to people.
Mind you, it's even trickier with the people with personal service companies who are calling for the government to make up not just the loss of pay from their company but also the loss of dividends. My view of them is best left unstated ;)
And in passing I thought HMG were bounced into the offer for employees by the Nordic precedents. It seemed to me problematic.