Each company or MSP (as they are more commonly called) has specific requirements for W9s, 1099s, etc. You, and I, are Independent Contractors (IC), so we are not employees of any MSP or iSS, therefore no W2s will be issued. Since tax reporting is not generally required until you make $600 or more per year per employer (i.e. MSP in this case), you don't have to be too concerned.
However, all of the relevant information, including paperwork and tax items, are found in the contract you signed with each MSP. Read through those and then if you have additional questions contact the MSP directly, but read the contract first, most important.
Hope that is some help. Thanks for reading.