I would not consider holding aside money to buy on the dip to be a variant to DCA, even though buying on dips could be a way to supplement DCA.
Buying on dips is not a variant of DCA because it is different. It does not guarantee buying right away and as soon as you have money, but instead it conditions the buys for if the price dips.
Buying on the dip may or may not happen, since in order for buying on dip to take place the BTC price has to go down to the targeted price level in order for the buy(s) to execute. If the BTC price does not go down enough to reach the targeted amount(s), then the buy(s) do not execute.
DCA can be designed to buy as soon as you have money coming in, and it is not conditioned on price changes.
Waiting for dips is like doing technical analysis and wait for good time and price for entries. It's very different and opposite with core purposes of Dollar Cost Averaging strategy: To eliminate all technical analysis; to get rid of emotional and psychological effects on timing the market, finding good or best price for entry.
By opposite purpose of dip purchases compare to DCA purchase, I have enough reasons to say they are different strategies and I very agree with your opinion here too. This dip-waiting for purchases is only good for every experienced investors while with newbies, just do what DCA suggests: Learn fundamentals of Bitcoin, work for money and prepare your investment capital, use investment capital for regular purchases. It's how DCA strategy is about and created for.