No, taking a flexible lump sum won’t be an option if your pot is under £10,000 unless you have designated previously to flexi-access drawdown or taken a UFPLS. If you extinguish both your monies in both flexi-access drawdown and in non-flexi access drawdown your account will be closed (if only one is extinguished, the account remains open). Once your account is closed, any further payments will go into a new account, which will have to be more than £10,000 before you can take a flexible lump sum.
However you may be able to take as a small pot lump sum instead.