Saying that the whistleblower 'may' have worked for former VP Biden is the same as saying anyone in the intel community works for the current VP. In fact, it's like saying anyone who currently works in government works for the President.
The administration is currently clambering over themselves to name the whislteblower for the sole reason of trying to discredit them. To say they came forward because they are a 'never Trumper'. To say 'they have an affinity to Biden'.
What they won't say however is that the substance of the reporting is true, that the Trump administration partook in the attempted* extortion of a foreign nation for political/personal gain, and the subsequent cover up.
*Not taking into account that there may be evidence of previous successful attempts of extortion against Ukraine.