When you use bind, all the identifiers you reference in the instantiation are from the target’s perspective, that includes the parameter override.
module flop
#(parameter width = 1)
(input wire [width-1:0] d,
input wire clk,
input wire rst_n,
output wire [width-1:0] q
);
endmodule : flop
module top;
typedef logic [7:0] uint8_t;
typedef logic [15:0] uint16_t;
logic clk, rst_n;
uint8_t d8,q8;
uint16_t d16, q16;
flop #(8) u8(.clk, .rst_n, .d(d8), .q(q8));
flop #(16) u16(.clk, .rst_n, .d(d16), .q(q16));
bind flop
meta_flop_metastability_injector_if #(.WIDTH(width)) i0 (
.meta_ff_d (d),
.dst_clk (clk),
.dst_rst_n (rst_n),
.meta_ff_q (q)
);
endmodule : top
interface meta_flop_metastability_injector_if
#(parameter WIDTH = 1)(
input logic [WIDTH-1:0] meta_ff_d,
input logic dst_clk,
input logic dst_rst_n,
output logic [WIDTH-1:0] meta_ff_q
);
initial $display("hello from %m WIDTH: %0d",WIDTH);
endinterface : meta_flop_metastability_injector_if