Is the verse permitting Khul' abrogated?

Primary text

The claim that Quran 2:229 (regarding Khul') is abrogated by Quran 4:20 ({Wa 'in turidu istibdala zawjin makana zawj}) is invalid. For abrogation to be established, proof of impossibility of reconciliation between the verses and the superseding verse being later in revelation must be proven, neither of which has been established.