This is remarkable, isn't it?
It's a classic Nigeria-style manufactured crisis. The banks are quite clearly colluding with large corporations and BDCs to create an artificial scarcity of new naira notes that is now complicating economic activity during an election season.
The intent could have been to deprive corrupt politicians from having the ability to rig the election (buy buying votes or paying those who count the votes) next month (since the cash they currently hold would be invalid by then, and though they could deposit the cash that flow of funds is then tracked).
It will be interesting to see after the election what the next president's stance will be regarding the push for a cashless economy and their CBDC.