Well that is highly unusual TOS. I can't remember any TOS of any service that would say if your email changes, your access to services will be nixed. There are many other examples where this can't work even with private email addresses. Domain US requires users to be physically in the US. If you happen to have an email with domain ending .US and you move to a a different country, you may not be able to access that email account any longer.
Aside from this strange and weird regarding the LTD accounts (which I don't own anyhow), the restriction seems to apply to any account, even if I pay subscription or have the free basic account. So basically if my email changes, I have to let this account go and have to open a new account.
I don't know if I can export existing workflows into the new account, but the idea of having to actually do so much work to do that makes me question the intention behind this.
So.... Since I can't change the email, provide me the button to delete the account. GDPR anybody? I know you are in India but that doesn't mean you should ignore GDPR because it can bite later on.
I tried to setup a new account but I never receive the confirmation email. Maybe because I already have another account with the same IP address?
Scratching my head.