Nitpick (!): Article and attachments do not prove Obama FDA purchased the heads, only that they received a quote.

Attachments show FDA received 18 liver-thymus pairs between 10/12 and 9/13, the first year, paying between $580 and $685 each, and had plans to do this the four years following. In 9/14 they ordered another 12 liver-thymus pairs. I do not see proof of receipt or payments in other years within the documents, but FDA requested another quote as late as 7/17 for 16 more organ pairs. So the Trump FDA may have been complicit as well, but they terminated the program 9/18 citing 42 USC 289g-2 ("Prohibitions regarding human fetal tissue", criminalizing acquisition; exemption had earlier been sought from an Institutional Review Board, apparently an NIH department, but the FDA apparently began to doubt the applicability of the exemption).

A primary researcher was Kristina E. Howard, who also publishes about Cytokine Release Syndrome (!) in relation to these "humanized mouse models". In 9/18 she and her peers published that 24 humanized mice died as an "unexpected" result (typically yeast infection), or else were euthanized, within 14 days of the surgery, so you can see how fast they burned through the organs, and this one probably was Trump-era research. Apparently there were several articles that could be generated from this event and similar ones though. There is a lot more to this rabbit hole.