No, the profile won't stay forever on their servers. If you leave the account for a certain time without logging in, then developers will consider the profile as being abandoned. After this process, the system will automatically wipe the profile from their servers. If you want additional information, access the application then go to ToS or Privacy. Everything should be detailed on that section of the software.
For more information, contact the developer at the following address: firstname.lastname@example.org