Previously you didn't have 10 days to find a job when you were fired. Based on USCIS rules previously, you had to be employed the day you file your H1 transfer. So in case you are fired, and if uscis asked for your latest pay stubs covering your employment of date of filing, you would need to leave the country, file it again and come back in.

When I filed an H1 for my startup, they issued a Request for Evidence just because the documentation mentioned our investor pitch "founder previously employed by LinkedIn". They thought I had already quit my job. Luckily I was still employed and was able to send the pay stubs.