Yes.
I’m not sure of the specific LastPass hack you refer to but with Kee Vault, sensitive data NEVER leaves the devices you control, and this is provable because unlike LastPass it is all open source! It is stored remotely only in an encrypted format that can’t be decrypted. There’s simply nothing of interest to find in the Kee Vault systems bar your email address (which as we explain elsewhere is protected with what is probably a record-breaking level of security, certainly far beyond any service or bank I’ve come across).
Nothing will change unless you ask it to. Kee Vault is an additional password storage option rather a replacement for the existing KeePass storage option. You can’t accidentally move your existing data into Kee Vault.
This is a similar question to Can we block upgrade to Kee version 3 but the initial question/motivation is different so I’ll keep them separate at least for the time being to aid discovery but I think it’s worth a mention.