What do you mean by "emails would break"? They would be rejected by Googles MX servers, and the sending server would relay a bounce message to the sender explaining the problem... That is just a normal function of email.

All MX servers have arbitrary limits. Those limits can be increased/reduced at will without "breaking email"

It is already a common case that people send emails which are larger than the receiving system is willing to accept and are therefore rejected. They then receive a bounce and make alternative arrangements for transferring the file.