The answer is almost certainly no.
An awful lot of UK employment law comes from the EU, including discrimination rights, collective consultation obligations, transfer of undertakings regulations, family leave, working time regulations and duties to agency workers. In theory, the UK government could repeal all of this, but it is very unlikely it will do so.
A lot of EU law simply replaced UK law, for example UK equal pay, race and disability discrimination laws proceeded EU anti-discrimination obligations. The right of return from maternity leave existed before EU maternity leave rights were implemented. The government is unlikely to want to row back on these protections.
A lot of employment law is popular, both with employees and employers, such as family leave, discrimination rights and paid holiday.
We are also likely to have to adhere to a certain amount of EU employment and social protection regulation to continue to trade with the EU.
The sheer complexity of having to disentangle the UK from its EU commitments will make it much more likely that the UK government will simply incorporate current EU employment law into UK law on exit and there will be little if any change.