There is no technical reason a 3050 system can't take up to the max (64G) of RAM -- that said, by the time you go to buy next year, the M15 R7 will likely be either history or on the way out, replaced by a new system with a 13th generation CPU, so you  will need to see what the specifications on that model are before deciding.  It's not out of the question the 3050 GPU may also be history by then as well.  
I'm starting to look into the next upgrade system I'm going to buy, probably some time next year.  I'm planning to stick with the m15 line, having had very good results with both the original M15, and my current M15 R3. Looking at the available options, the bottom end video chip: the 3050 Ti will be plenty enough, since for the vast majority of time, I have an eGPU attached, with a 3070 Ti card in it  The problem with that is the only configurations that have that video chip also only have 16 Gb memory, and for some workloads I have, I find that the 32 Gb in my current M15 R3 really makes a difference.  Most notably large builds in Visual Studio are significantly faster with the additional memory. So, I'm thinking about getting the base model, and then getting a memory upgrade directly from Crucial, which also has the advantage of being cheaper than the incremental cost of buying the memory from Dell.  Is there any reason that the 3050 Ti card will not function in a system with memory upgraded to 32 (or possibly 64) Gb of memory.  I recognize that these options are not available directly for purchase, but is that just to keep the number of options sane, or is there some technical limit that prohibits a 3050 Ti system from functioning when more than 16 Gb of memory is installed.
m15 R7, video chip selection and memory upgrades