The reasonableness of the action is heavily dependent upon the actual use of the wetlands and their role in the larger ecological environment. Land surveys would need to be done to show the impact of such wetland mitigation as Disney is proposing. This will be considered the expansion loss. Additionally the protected area being considered for future protection would also need an in-depth review to determine the chance of loss for the particular tract of land. This is the protection gain. If the protection gain is greater than the expansion loss, then the expansion could be seen as reasonable.
Given the above argument I do not believe the expansion is necessary or reasonable in all most any given scenario. There are many reasons, but three top the list. Due to these reasons I would strongly object to any expansion.
First, Disney is a multi-billion dollar company. They may desire to expand for additional revenue and may very well argue more tourism would boost the local economy. However due tot the tremendous size of the company it cannot reasonably argue economic protection or production as a viable argument. Forcing Disney to expand in new economic areas can enhance the financial stability of a larger area.
Second, the value of wetlands cannot always be quantified by the owner. The wetlands provide flood protection, provide for fishing industry, and allow living space for a diverse ecological spectrum which may include protected species. The owner of the property may not see the immediate value, but violating the area may endanger animals or another persons benefit from the land.
The final argument against it is directly tied to the second. Destroying the land may, and probably will, violate the benefit another person receives from the land. There are legal precedence in place to prevent this type of land degradation because of the adverse effects.
The final review of the problem shows although it could be considered reasonable with a strict mathematical view, it does not stand to the test of reasonable expectations because the expansion loss outweighs the protection gain.