The talk of this interim defense assets, whether interim fighters, interim frigates or interim submarine are aiming as stop gap to fill existing hole in defense assets.
For fighters remember TNI-AU basically already have one sq short since 2015 when the last F-5 taken out, and basically no replacement. The Hawk 209 eventough still fill two sq, but realities both sq only have effective strengths of slightly just one full sq. This is why the hawk being rumours going to be pull in one sq. So just to fill existing capabilities, there're immediate need to fill gap of two sq which now being hope to fill it by this interim fighters.
This is not talk of additional capabilities. There's also possibilities the Flankers sq going to be run down soon, as with Russian production now full to fill their own war needs thus potentially hinder of their parts support flow. Thus questions whether TNI-AU can still keep the Flankers fully operational. Thus on top the two sq I mention above, there's potential for another one soon.
Even if those 42 Rafale or 36 F-15EX/F-16V come to fruition, it will still need to get by end of this decade to get them fully operational. By that time potentially those 2 Hawk 209 sq need to get replace plus 1 F-5 sq and potentially 1 Flankers sq. Thus 4 sq even need potentially fill the gap before new assets come.
Whether 3-4 sq need to fill by interim sq coming from all Mirage 2000 (in paper it can be happen if they can get the deal from both Qatar and UAE), it is something that need to be ready ASAP. Those Gulf Mirage is soon will be available. That's basically the attractions. Whether this deals going to be included as part deal with Dasault, that's I believe open to negotiation.