While they didn't specify the technical details, as a developer I can make a reasonably educated guess as to what those details are. The game executables formerly using SecureROM for DRM protection are dynamically linked to the DLL libraries that implement it, which would be the normal way to do something like this. GOG most likely either does not have the source code for the game (most likely scenario), or they are currently technically unable to rebuild it for $reasons, but I am going to assume the former - that they don't have the source code as that is the usual case with games GOG distributes.
Warner either gave them a back door or something to disable and make the DRM inert, but since the game executables are linked to the libraries, until they are able to recompile new binaries that have disabled support for SecureROM, the library must be provided so that the dynamic linker can resolve the symbols from the library in the offset table - otherwise the operating system will be unable to execute the binary.
Since the game is playable with the DRM disabled in this fashion, the two companies chose to put it out there as-is for the time being as the quickest solution to the problem and as a temporary measure, with plans to later put out an update which is either a recompiled binary that no longer links to the SecuROM DLL, or the only other option would be to have some hacker at GOG, debug the executable and basically manually hack out all of the hooks that are in the executable that link to the DLL which is a potentially time consuming process to do and then to quality test the resulting hacked executable.
They're most likely not going to go into that level of technical detail in a public forum about the inner workings of how they do things, and quite frankly most non-programmers and even many actual programmers wont have a clue what any of it means anyway.
Since the existence of the DLL is just to make the executable happy (more accurately the OS's dynamic linker), it is effectively just a "stub" that does nothing other than sit there and take up a small amount of disk space until they're able to resolve the underlying technical issue in a superior manner. The alternative to doing what they've done would be to have not released the game at all over an extremely minor and temporary issue just to wait until a better solution could be implemented when the existing solution should work fine for the majority of people and should not cause any problems. If it does cause problems, that's unfortunate but doesn't make anyone any worse off than if they held back from releasing it for months to hack the executables.
The details might be slightly different than what I've hypothesized here, but the general idea is more likely than not very close to what I've said. If people are encountering a real world problem with the game loading, then they've got a right to be disappointed and should contact technical support to seek a workaround. If people are upset because a DLL file that is harmless is taking up a few kilobytes or megabytes of disk space in a world where multi-terabyte disks go for $100 or so, then they might possibly have bigger problems. :)
At any rate, this falls into the category of extremely trivial issue that triggers people's negative emotions because the word DRM is mentioned.
