No. The main documented cross-border arrangement is Eskom supplying electricity to Botswana, and Botswana is often a net importer during shortages, according to Southern African Power Pool (SAPP) reporting. Neither the Government of Botswana portal nor Botswana Power Corporation (BPC) has announced any Botswana-to–South Africa supply suspension.
Public, primary channels do not support the idea that Botswana is currently supplying South Africa with electricity. The Government of Botswana portal and Botswana Power Corporation’s own updates focus on Botswana’s domestic reliability problems—such as forced outages and maintenance at Morupule B—and contain no statement about exporting power to South Africa or suspending such exports.
Regional power-trade context also cuts against the claim’s premise. Evidence referenced in the verification (including SAPP reporting) characterizes Botswana as a net importer during periods of constraint, with the better-documented bilateral relationship being Eskom supplying Botswana rather than Botswana supplying Eskom/South Africa. Without a credible primary source confirming an active Botswana-to–South Africa supply agreement, there is no basis for claims that BPC “cut” or “suspended” electricity to South Africa.