They definitely can, as anybody could, for a short enough period of time. The only ones betting they'll be able to sustain it for a long period are the ones paying the currently very inflated price for ram.
but it's not a short term deal. funny enough, there's a cohort of bonds that never even made one payment. They are called first payment default bonds. There is a cheekier nickname for them, but it escapes me at the moment.
The market doesn't believe they can pay for the Oracle cloud deal. Why do these vendors believe OpenAI can pay for 40% of the world's DRAM?