Gigaphoton is also a DUV laser supplier, so it is possibly doubly screwed by ASML this way. it is too tempting to put Cymer lasers in all its tools. I don't know if any customer would insist on Gigaphoton.
But this is still a desperation move by ASML related to EUV. However, it does offer some strategic supply chain benefits for its current DUV market. Still, the cost of 2.5-2.6 billion USD is significant.