Funny you would say that, because if you read the indictment, these people did actually deposit Monero on one exchange:
> VCE 4 Account 2 was entirely funded by approximately 13,200 XMR via approximately 21 transactions that took place between in or around November 2017 and March 2019.
> Another account at VCE 4 (“VCE 4 Account 3”) was created on or about November 20, 2017, and was registered in the name of another Russian national and under another Russian email address. VCE 4 Account 3 was entirely funded by approximately 6,870 XMR, via approximately 10 transactions that took place between in or around November 2017 and April 2019.
> The XMR deposited into VCE 4 Account 2 and VCE 4 Account 3 was all converted to BTC and then withdrawn, consistent with chain hopping. The same method was used to liquidate the funds from the VCE 1 accounts as described above.
> VCE 4 Account 2 was entirely funded by approximately 13,200 XMR via approximately 21 transactions that took place between in or around November 2017 and March 2019.
> Another account at VCE 4 (“VCE 4 Account 3”) was created on or about November 20, 2017, and was registered in the name of another Russian national and under another Russian email address. VCE 4 Account 3 was entirely funded by approximately 6,870 XMR, via approximately 10 transactions that took place between in or around November 2017 and April 2019.
> The XMR deposited into VCE 4 Account 2 and VCE 4 Account 3 was all converted to BTC and then withdrawn, consistent with chain hopping. The same method was used to liquidate the funds from the VCE 1 accounts as described above.