Update 4/15: No digital comics of Scooby-Doo Where Are You? are being published during this time either. One can presume from this that the series has been temporarily been put on hiatus until the end of the COVID-19 pandemic.
With many US states enacting shelter-in-place orders which do not allow individuals to leave their homes except for essential duties, Diamond Comics, the distributor of DC Comics, has announced that they are completely halting shipping new comics until the COVID-19 pandemic is over. This is partially due to many comic book stores having to shut down during this time, and travel restrictions being placed on those who ship comics to local grocery stores. Scooby-Doo, Where Are You? #104 and #105 were scheduled for April 15, 2020 and June 17, 2020, respectively. Given Diamond Comics' announcement to stop shipping comics "until at least July," this means that no physical copies of these comics will be available for the foreseeable future.
In addition, DC Comics has announced that in light of this, they will be going fully digital. Scooby-Doo, Where Are You? #104 and #105 have not specifically come up in any official communications, but it can be presumed that digital copies will still be released on April 15 and June 17, respectively.